All of us at Mark English architects, and most of the rest of our colleagues, are involved in thinking about and implementing Green Building practices. Last year the Greenbuild Expo arrived in San Francisco, and several of our employees attended. One of them is Benjamin Todt, a German architectural intern.  Germany is a leading proponent of Green design, and leads much of the world in Passivehaus design, net-zero design, solar and wind alternative energy sources.  I thought it would be interesting to see the Expo through Ben’s eyes.  The following are his observations:

“When I first visited the Greenbuild website to sign up, I became very excited: The prospect of spending three days in educational sessions at one of the world’s largest conferences dedicated to green buildings with building professionals from around the world sounded thrilling. Having just received my Bachelor’s degree I could not wait to learn more about the likes of cool towers, building envelope design and natural ventilation. At the time I registered for the sessions, some of the sessions about architecture specific topics were already full so I had to sign up for a few sessions that sounded less interesting like Austin’s sustainability measures and Tony Fadell’s talk about his beautiful but seemingly pointless attempt to redesign the thermostat.

Greenbuild itself then actually started out with a bang. Or more precisely with the opening plenary featuring Biz Stone, Co-Founder of Twitter, and Rick Fredrizzi, President of USGBC, among others. While the moderators of the event wanted to hear that Twitter caused recent political changes, Biz Stone replied in his relaxed manner that all it is really doing is facilitating communication and collaboration, not initiating any human needs. He then mentioned that eventually social media will lead to a smaller world in which it will be more appropriate to think of the world in terms of humanity as a whole instead of nations and countries. And as the world becomes more interconnected he thinks that marketing will shift to a new model where companies use the majority of the marketing budget to do good things in the world and use the rest of it to make sure that we all know about it. He then concluded by saying that people don’t care about “green” when they are oppressed or are starving to death. At this point I was not sure how this related to Greenbuild. But then Rick Fredrizzi made a similar point: While companies are a central part of the problem now, they have to become central part of the solution as well. In essence he said that the green movement can only be successful if it achieves market transformation in collaboration with the economy. His infectious energy and passion, paired with steadfast determination gave me the feeling that the American green movement was in good hands.

After this unexpectedly broad but energizing intro, I was looking forward to equally enthusiastic but much more precise and architecture specific presentations. The sessions that I had looked forward to the most, the ones that were supposed to deliver in depth, cutting-edge knowledge about topics that I had heard about a little in college, fell far short of this. Instead of learning how to exactly design a building envelope that can stand the extreme climate of Saudi Arabia, I was let down with many pretty renderings and a couple of undergraduate-level principles of shading. Instead of learning how to exactly design a building in San Francisco using natural ventilation, I was served with a teaspoon of information that I could have gained from simply visiting the building and looking at it. And instead of gaining any significant new insight into cool towers, the presenters decided to settle for a shallow report of their projects and show that they were unable to integrate the cool towers into the building design in an esthetically acceptable way. Making it an even less satisfying experience, the energy with which they all presented their, in essence truly applaudable, work was as low as the energy consumption of their buildings. Or lower.

In stark contrast to this, Lucia Athens, Chief Sustainable Officer of the city of Austin, gave a riveting talk that went far beyond the sustainability of a single building. Long before she started her work, Austin had dozens of stand-alone sustainability initiatives. But the problem was that the different organizations were not connected or didn’t even know about the existence of other organizations in Austin. So she decided to bundle all 180+ sustainability initiatives and created one recognizable logo. Calling it “rethink Austin for a bright green future” she puts her “holy trinity” of People (Equity), Planet (Environment) and Prosperity (Economy) front and center. With this approach she wants to tackle Austin’s extensive list of problems including huge population growth, poverty, obesity, lack of parks and poor transportation system among many others. She concluded with a set of guidelines, which she uses in her quest: “Build a frame”(start where you are, create a system), “Tell a story” (measure progress, celebrate success) and “Think big” (outside box, people matter, fun). Lucia’s idealism is infectious and she demonstrates on a daily basis how sustainability can go far beyond a city’s buildings.

Once Lucia has put people into homes, they can start to worry about their energy bills. And that is where Tony Fadell and his Nest thermostat come into play. I had heard of his product before but admittedly I had never truly understood its revolutionary quality. At first glance it actually is only a beautiful thermostat. You can install it and simply pretend it is like the other thermostat you used before. But Tony made a different experience: people actually start to engage with their thermostat. They start caring about it. The more people interact with it, the more it learns about the occupants of the building. It can set the right temperature considering the time of the day, weather, the occupant’s behavior and more. That helps you to save money by just using it as a regular thermostat. Tony thinks, and being a former Apple employee he should know, that the reason for its success is the fact that it is emotional which makes people want to engage with it. He sees it as a starting point for people to learn more about water, electricity and insulation. But what is truly spectacular about this product is a tiny green leaf that only appears when you set your temperature slightly below your usual comfort temperature. People want to see the green leaf, be rewarded, and that way they save energy and money. Just because of a few green pixels. Spectacular.

Eventually Greenbuild 2012 ended on a high and unexpected note. Very high. Very unexpected. It ended with Jane McGonigal. Jane McGonigal is the Director of Game Research and Development at the Institute for the Future. She said that the world spends 100 million hours every three weeks on playing Angry Birds. Why is that significant? Because it took 100 million hours to create Wikipedia. Wow. We could create something as complex as Wikipedia every three weeks by just not opening the app and being productive in a meaningful way instead. She pointed out how gamers are open to failure, fail constantly, try hard to eventually get the big reward, the epic win. Additionally, gamers are highly engaged in their games. Jane wants to find ways to bring those qualities of gamers into the real world to solve real world problems, Environmental problems, for example.

So what do I know now, after Greenbuild, that I didn’t know before? I don’t know much more about new, surprising ways to make a building “green”. Maybe that’s because I went to the wrong sessions or because there just isn’t that much more to learn about sustainable building techniques. It’s possible that we already know enough and all we need to do is implement it in both new and existing buildings. But that’s not something Greenbuild can do. That’s something only professionals can do in their job. What it did, though, was teaching me that much of the success of the green movement will depend on everyone else but the people attending Greenbuild. We already knew how important building, living, thinking green was. In many ways Greenbuild preached to the choir. And yet it also made room for people like Lucia Athens, Tony Fadell and Jane McGonigal who tackle the problems in a fresh, innovative way. It’s because of them that everyone else but the people attending Greenbuild can become part of the movement. For me, Greenbuild’s biggest accomplishments were to open my mind to the necessity of getting all the other people on board and introducing me to surprising new ways of how to do so.

Thank you, Greenbuild 2012.”

-Benjamin Todt

A Sustainable Home is a Safer Home

Occasionally at Green Compliance Plus, we host guest articles from members of our community. Here is one perspective from the Insurance Industry.

People who are building or already own sustainable homes understand that their homes will use less energy and water. What they might not realize is that their homes also are much safer than conventionally built homes. Or that the enhanced safety features can result in less risk for home insurers and better rates for coverage.

That’s true whether the houses are certified by Leadership in Energy and Environmental Design, ENERGY STAR for New Homes, Enterprise Green Communities or another authority. Here are some of the features of green homes that make them sustainable and how they reduce risk for home insurance providers.

Steel and aluminum roofs

Many people seek LEED certification for their homes in part by installing roofs that use steel or aluminum – both of which are highly reflective, energy-conserving materials – on at least 75% of their roof’s surface. But in addition to those qualities, roofs made of steel and aluminum are more fire-resistant and stronger.

This matters because severe thunderstorms caused nearly $15 billion in insured losses in 2012, according to the Insurance Information Institute. More durable roofs aren’t nearly so susceptible to storm damage, meaning they don’t carry nearly the risk of conventionally built ones. That could easily mean lower insurance premiums for the sustainable homeowner.

Modern electrical systems

Green homes feature electrical systems designed for energy efficiency. But these modern systems also result in less risk of fire. The National Fire Protection Association has statistics that show what this can mean: There are nearly 500,000 structure fires every year, with a residential house fire breaking out every 82 seconds.

In many cases, the cause for these fires is assigned to faulty electrical systems that depend on outdated fuse boxes, ungrounded power outlets and other problems. The cost is staggering – the average claim is about $30,000. Because they are newer and use safer technology, sustainable energy systems are much safer than older conventional systems.

Updated heating and cooling systems

Modern heating, ventilation and cooling systems result in a number of points for green certification programs because they use less energy and produce better air quality. But again, they also have side benefits that contribute to safety.

Consider that another chief culprit in electrical fires is the failure of air conditioning systems. The NFPA says such failures contribute to about 2,500 home fires every year. Heating system failures in winter can lead to frozen pipes that can burst and cause costly water damage in a home. Updating these systems greatly reduces the risk of fire and water damage from seasonal weather.

Better plumbing

Many homeowners seeking green certification install water-efficient toilets and other plumbing that uses less water. Again, that also reduces the chance of a leak or other malfunction that could lead to water damage in a home. The III reports that water damage claims make up nearly 25% of home insurance claims, with an average cost of $7,000 each.

Cutting these common risks often means green homeowners will qualify for preferred homeowners insurance policies, which have lower rates. The lower risks for green homeowners can even benefit other policyholders.

In 2011, providers used 92% of the $62 billion they collected in premiums to pay claims. If there are fewer and smaller claims because sustainable homes are safer and sturdier, insurers might not have to collect as much in premiums. Ultimately, that could mean lower rates for all homeowners.

This article was contributed by Arthur Murray, who writes for HomeInsurance.com. Arthur has more than 30 years of experience writing for newspapers and magazines. He graduated from the University of North Carolina in 1979 with a bachelor’s degree in Journalism.

So what do daring designs have to do with Title 24 energy compliance? Well, they need a lot of special attention because they often feature expansive windows to celebrate the crisp and brilliant California sunshine, and in the North Bay area, they let in gorgeous views as well. Vaulted ceilings, also a common design feature, can require special attention to the roof assembly to ensure that there’s enough space to fit the necessary amount of insulation.

A Dramatic Second-Story Addition

The stats: 4,000 SF total, including their proposed 768-SF addition, a master suite. This was a ranch house north of San Francisco, built 1962. House + House had remodeled it 18 years ago, for a previous owner. The place was recently sold, and the new owner approached House + House for a second expansion.

The additional conditioned space consisted of an expansion outwards on the second, over the first. This new interior space was all contiguous – which could help the energy model. Thankfully, the local jurisdiction had no “beyond code” green ordinances that would apply to Additions. So we just had to make compliance, not beat it by 15% or more.

First floor plan of a custom home remodel by San Francisco architects Steven and Cathi House of House+House Architects. House+House had actually remodeled the same house for a former owner 18 years previously. Although the wraparound porch was not included in the energy model, it is a key design feature in this remodeling project.

Can We Keep the Existing Heating System?

The owners wanted to keep the existing furnace and water heater, which meant we might have to assume legacy numbers (bad for compliance). There was no cooling system. The drawings I received showed two mechanical areas, both inside conditioned space (good for compliance). Vaulted ceilings on the second floor portion of the addition meant that the duct chase up there could also be claimed as being within conditioned space for additional credit.

The project had a very tight budget. We needed to weigh the cost of additional measures carefully. The fact that there was no cooling system meant that the house probably didn’t need one due to shade trees – but, in Title 24 you can’t count those shade trees. This can result in artificially high cooling loads (bad for compliance).

The majority of the addition was on the second floor, and involved adding new floor space and raising the ceilings on much of the existing space. Design by Steven and Cathi House of House+House Architects.

The Need to Avoid a Whole-House Model

We were concerned that if we had to run it as a Whole House, that we would have to take into account the original conditions from 1962 and 1993 respectively. With any existing home built more than 10 years ago, if the windows are not known, we generally have to assume the worst: aluminum single glazed. If we can claim the windows as wood framed that’s a little better, but it’s still probably not low-e insulating glass. Insulation levels in existing walls would have to be a lookup based on the dates built. So we had a strong mandate to make it work as Addition Alone – but ultimately, the goal was to keep construction costs down.

The first step was to see if by some chance it qualified for prescriptive compliance, which would get us out of a lot of extra steps. If the overall glazing is under 20% of total conditioned floor area for whole house or for the addition alone – that would be the path of least resistance. No dice.

Let the Trade-Offs Begin

The preliminary drawings included many beautiful renderings that were very helpful in getting a good holistic sense of the space. The architects were still refining the elevations and window schedule with exact window dimensions, so we began the energy modeling without them. One unusual design feature was the angled wings, and hidden alcoves. This usually means that we need separate elevations for each wall, and the architects were still refining those drawings.

The angled walls added a new challenge as well, in that it can be difficult to approximate the window widths when working from a foreshortened elevation angle. Usually I can take an educated guess at the openings, but for difficult projects, there’s always the chance that a plan checker could call the energy report into question, so I wanted every assumption to be well-documented and defensible. One of those assumptions was to locate the heating ducts within conditioned space (big compliance credit).

There was also an indication on those drawings that the owner **might** be adding a second furnace in the garage to feed the new addition space. I advised House+House to find a way of enclosing that furnace within conditioned space so we could keep that duct credit either way. They were planning to use Milgard vinyl framed windows, which was good news; Milgard offers many options for varying grades of efficiency.

Windows can be an easy but expensive way to bump up the score. Sometimes the better window packages are a lot more expensive, so any time we run a project with better than standard windows, we have to ask the architects to ascertain the additional cost, wait for them to get a new quote from the manufacturer, discuss it with their client, and that can take a certain amount of time. If we’re trying all sorts of other options at the same time, it can take a lot of extra time.

The master suite in this second-story addition by House+House Architects features expansive windows and vaulted ceilings.

The Baseline Wasn’t Bad, But…

To my surprise, the baseline trial (assuming the worst for anything not known) didn’t quite make it but it wasn’t off by that much: -7.1%, with more of the shortfall on the heating side. Since they wanted to keep the furnace, the first thing we tried was upping the insulation in the walls from the minimum required R13 to R15. That brought us to -4.2%.

The roof cavity was small and we maxed that out at R30, even with spray foam. So we couldn’t go up on the roof insulation. Next, we tried an 95% efficient furnace instead of the legacy 80% one. It’s easier to swap out a furnace than it is to upgrade every window or do HERS tests. That brought us to +4.5% over.

Well, it turned out that replacing the furnace was not an option, at least not right then. At least I had the actual make and model number, a Carrier furnace. I called Carrier to see if by chance that was one of their more efficient models – but they eventually got back to me several days later to confirm that no, it was a baseline 80% efficient model. Foiled again!

A Lot of Discussion With the Architect

As I’m reviewing my modeling notes, one thing that stands out is that there was a lot more back and forth with the architect than there were actual modeling trials. There were several different measures which, combined in various ways, could have yielded a passing score: replacing the furnace, ducts in conditioned space, R15 walls, the low-leakage duct test (if ducts couldn’t be in conditioned space), and more efficient windows.

It turned out that the ducts could only be claimed as “combination space”, meaning portions of them were within the conditioned building envelope, but not all of them. That still yielded a compliance credit, but a smaller one. We might have to resort to a HERS duct blaster test – which now, in addition to having another thing to ensure during construction, also requires online registry with CalCERTS.

The architects didn’t yet know how the ductwork for the new addition would be configured. They were expecting, not unreasonably, that this would be worked out in the field by the contractor. But, we needed the energy report now, in order to get the building permit, and we didn’t want to commit to anything that would turn out to be impossible later on. We didn’t even know if the new space would run off the same system or not, and since no work was planned on the existing ductwork, that introduced the risk of failing the HERS duct test – and we’d have to start all over again on the energy compliance. Not good.

What Finally Worked for Everyone

Eventually I think we got it to work with the following combination of options:

• Furnace efficiency dialed back to .80 AFUE (existing furnace)
• Ducts remain in conditioned space
• Exterior walls in addition insulation at R15
• Windows are now .30 U value (Milgard 3DMax package)
• NO duct test, but one visual duct inspection

CalCERTS: The Final Hoop, We Hope

And then it turned out we needed the CalCERTS registry after all, and I found out a new knotty twist. For a remodel, the energy consultant has to get the homeowner to self-register (with a driver’s license and signed form) before he or she can even create the project online, much less upload the energy report and get the watermark! Fortunately, the owner was on the ball and responded quickly. If he’d been offline or on vacation in Tahiti, the project could easily have stalled.

The CalCERTS folks had designed their system to handle a more typical workflow which is quite different from these one-off, custom projects. So it expected to see all kinds of data like a builder name, HVAC installer name, and permit date, which we typically never have prior to submittal. Fortunately, the CalCERTS folks are always very nice and helpful over the phone, and have always helped out. It’s a new process for them, too.

Although it's not factored for energy modeling purposes, because it shades an existing area of the house that was not included in the model, the wraparound porch is a unifying design element that ties together all the fragmented pieces of the house that were added on over the years. The curved outset wall on the right can also be seen on the first floor elevation.

The problem with additions is that you have less to work with if the project doesn’t comply. Small additions are the hardest, and alterations are even worse, because you’re not adding any conditioned area. If it doesn’t qualify for prescriptive (simple but rigid), you have no choice but to do a whole house energy model. And with the energy model method, you have to justify the values used for the rest of the house that’s not being touched, and which may be built to a long-obsolete energy standard. Those existing R-0 walls can cost you.

Local Green Building Requirements Can Differ

Local green building ordinances can vary in very unpredictable ways. Some areas are adopting BuildItGreen’s GreenPoint Rated system, which at a minimum requires 15% over compliance for new construction. That alone means an energy model, since you can’t “exceed” compliance using the prescriptive form. With the simpler prescriptive form it’s very black and white: either you meet every requirement, or you don’t comply – there’s no extra credit in one area to make up for shortfalls in another.

And it’s not just the GreenPoint checklist that the jurisdictions want, either. If a local Building department is using the GreenPoint Rated system, they often want to see the full follow-through, with a third-party rater who checks up on the project all the way through construction. Others are adopting CALGreen optional tiers, which have pretty much the same measures as BuildItGreen, but it’s structured differently – and that can also have an impact. A locality can even adopt a green building ordinance all on its own that doesn’t reference these systems, although that’s less likely than choosing one standard and then piggybacking further requirements on top of it.

For example, Portola Valley has added a sliding scale GreenPoint score where the larger the house, the more GreenPoints it needs. One of our recent Title 24 projects, a new 6,000 square foot house with 40% glazing to floor area, and metal framed windows (less efficient) required 172 GreenPoints, and in order to make that, we needed to get that house to exceed Title 24 by 35%!

At least with that project, we had the whole house design to work with. We got that project early in the design phase, so we could work with the architect to specify better windows, test out the impact of various system efficiencies, and discuss the additional credits of HERS testing with the assurance that it would likely pass all those tests. With additions, you have to perform the same miracles without altering the majority of the building. And you never know what a local green building ordinance may require.

Even Interior Remodels Now Require Title 24 – in Burlingame

Here’s an example that just came up, and is the subject of this case study. One of our recent Title 24 projects, a remodel of a private home in Burlingame, CA, was mainly an interior remodel. Who knew that Burlingame has an expenditure threshold where any construction project costing over $50K now triggers a Title 24 compliance requirement that has to beat the standard by 15%? And a GreenPoint Checklist with a minimum of 50 points? It’s not like they’re even changing the building envelope.

Well, Mark ran this project and it was -174% behind. “It simply couldn’t be done,” he told me. “It was a nice Mid-Century Modern home with lots of glass everywhere, and vintage insulation. Even if we replaced every window and the heating system, we wouldn’t even make the baseline, let alone 15% over.”

The home's existing condition, before the interior remodel which had no impact on the exterior envelope whatsoever, failed Title 24 by an impossible margin. Note that California's energy code assumes a minimum 13 SEER cooling system, whether any cooling is installed or not.

Mark spoke to a Burlingame city Green Building official, who bluntly told him, “You can apply for a hardship exemption, but you’re not likely to get it.” The owner, a medical professional whom we’ll call Dr X, was already committed to making this project happen. This would have crushed the project completely – and for no justifiable reason.

Then, Mark had a brainstorm. He talked the owner into replacing the heating system with top-of-the-line efficient equipment, and then he created two separate reports: a “before” and an “after”. The “after” report was only (only!) -120% under, a 50% improvement! The home didn’t have any cooling system installed, so no help there. Title 24 assumes you have one even if you don’t, and penalizes accordingly.

The owner agreed to upgrade his heating system and got a 50% improvement.

A Happy Outcome

The owner then submitted the two reports to the City, along with a hardship application form – and to everyone’s astonishment, he got his permit. He wrote us a lovely handwritten note:

“Dear Mark,

Many thanks for all your work and suggestions. I turned in your Title 24 analysis and the hardship for with your wording plus additional palaver and got the permit Monday. It would have been a bleak Thanksgiving if I was still in a suspended state. I really appreciate everything you did.

Best,

Dr. X.”

Lessons Learned

What are the lessons to be learned from this exercise, aside from the fact that new regulations can have unanticipated consequences? Here is what we concluded:

1. Don’t assume that additions are easier than whole-house remodels. You have a lot less to work with and fewer opportunities to improve performance.
2. It’s very hard to get an addition to comply on its own.

Be told.

Impact of Poorly Designed Regulations Can Be Catastrophic

Mark English, ever the advocate for both architects and homeowners, put it this way. “You can’t inhibit people from upgrading their homes – it only kills the economy and prevents construction from happening at all. You can’t hold people hostage and force them to rebuild their entire house for some ridiculous bureaucratic rule that no one’s thought through. At the very least, Burlingame should raise that construction threshold to something like $200K, because any interior remodel, even a kitchen and master suite, can easily cost $125K and more – without any changes to the envelope.”

This goes back to one of our earlier articles on QII credits for spray foam – another “gotcha” that almost cost one of our Title 24 projects its compliance in the field – too late in the game to make it up easily through design or construction changes. The way regulatory processes work, the people writing these codes can’t anticipate their impact in the field, unless we bring it to their attention. I sure hope they see this article!

Apparently, up until around yesterday, the California Energy Commission did not officially recognize the QII test as valid for open-cell spray foam. Our insulation expert James Morshead of SDI Insulation actually sent me an urgent email yesterday with the news, saying:

Today the California Energy Commission stepped out of the 1980′s and into the 1990′s! The 1/2 pound density spray foam QII check list has finally been approved after long delays.

There will be further revisions and refinements but our State has finally caught up in its own way. They have finally acknowledged what the rest of the country has known and what we have known in our area for years; spray foam works whether its closed cell 2 pound density or open cell 1/2 pound density.

Now on to fixing the U-Value tables!

Active lobbying at the CEC is necessary

As usual, James was an endless trove of insider information. Apart from the news itself, the way that this came about was very revealing of the CEC’s  inner working processes. Most of us don’t understand how or why regulations are the way they are, or how agencies like the CEC solicit input from the public. Apparently one must be prepared to show up in Sacramento at multiple hearings, cultivate deep relationships with CEC staff, sift through the raft of proposed changes for the few items that might be relevant to your industry or situation, and be prepared to pounce on proposed changes with a formally structured submittal process. In other words, hire a full-time lobbyist.

A QII teaching case with the New Solar Homes rebate

We’ve run into some issues on the QII test before, where we’d called it out for extra credit on a Title 24 report on a project that was going for the New Solar Homes rebate. The house had to beat Title 24 by 15% to qualify. James Morshead was actually the insulation installer on that job, and clearly remembered how the HERS rater – NOT one of our Green Compliance Plus Affiliates – flatly refused to accept the low-density spray foam. Closed-cell was fine, but open-cell? No way. This was maybe the first time we’d ever used the QII credit, and nobody, including our other HERS raters, could tell us much about this obscure little omission that suddenly threatened the validity of the project’s energy compliance documentation – and the NSHP rebate. There was much tearing of hair and gnashing of teeth all around.

This close-up shows examples of open cell and closed cell spray foam, also known as low-density and high-density foam. Each cell in the high-density foam is closed, making it a better air barrier – which increases its insulating value.

Whys’ this QII change so darned important?

What are the ramifications of this change and how did it come about? “The recognition of open-cell spray foam has been in process for six and a half years,” said James. “We at SDI didn’t know how the CEC process worked. We thought the CEC would be actively looking at the market to incorporate new developments in a proactive way. But they’re not set up to do that. They’re set up to be reactive, influenced by lobbying input from stakeholders in the marketplace.”

He mentioned a long-ago fight between manufacturers of cellulose and fiberglass insulation, each of whom pushed to have their own products recognized as higher efficiency (higher R value) than the other. “That’s normal business. The CEC is a government agency, and that means that they’re encumbered themselves by a lot of regulatory process. They’re restricted by the system themselves. They rely on input from competing parties, and they solicit information by saying, ‘We want your input.’ They rely on the stakeholders to approach them and provide the necessary technical information.”

But presenting this input to the CEC can be an uphill battle. James mentioned meetings that would be cancelled without notice, web site meeting schedules that were not updated to reflect changes or cancellations, and a very skeptical audience. “They’re coming from an analytical and academic standpoint, but they’re NOT in the field.” And that’s the main point of this discussion, is that until the CEC actually went out to see a low-density spray foam installation, they didn’t believe it worked AT ALL. “They were writing regulations without ever having seen it in action.”

James went on to emphasize that he didn’t fault anyone at the CEC, in fact he admired their work and didn’t envy their task. They’re overworked, underfunded, well-intended, and very committed to the overall goals of helping California to achieve greater energy efficiency. They are doing their absolute best within cumbersome bureaucratic processes that they can’t change, either. To get an an idea of how slow the cycles are for code revisions, consider that the current version of the California energy code, the 2008 code, actually didn’t go into effect until 2010. And, some of its provisions weren’t enforced across the board until October of 2011.

Meritage Homes – a study in foam

Then we got on the topic of Meritage Homes, a high-end home developer who was apparently instrumental in adopting and demonstrating the real value of spray foam. Meritage’s Green FAQ page actually talks about the building envelope as separate from the appliances. James told me that Meritage had decided to use 100% spray foam in all its new developments. Their homes weren’t selling, because of the economy of course – not because the homes were bad. Nobody was buying anything, no one could get financing.

“But then, someone convinced them to foam their homes. The first batch was in Houston, TX. And the spray foam was so effective as an insulator that it ended up causing them some problems early on. Suddenly, all the A/C units in the foam-insulated homes were grossly oversized! Short cycling and such. And they had mold problems as well. But they also realized: OMG! this foam works way beyond the calcs!”

Meritage Homes is a high-end home development company that has implemented energy efficient building envelopes as part of the core design.

And that’s where we get back to the CEC, and the California energy code, which has all sorts of tables and appendices with the allowable thermal values that you can use for various types of wall assemblies and insulations: wood frame, metal frame, etc. (They even have an appendix table for straw bales now.) So, even if your insulation is NASA-quality, the CEC’s Joint Appendices might disallow the use of its true performance capabilities when doing home energy calculations. Which isn’t really fair, considering how difficult it’s been to get even ordinary home designs to meet current California energy standards.

The deconstructed home as sales tool

Most of the time, developers will have a few finished-off model homes that prospective buyers can walk through to see what their home will eventually look like once it’s built. But Meritage did something different. They had a model home with cutout walls to show the interior building assemblies, including studs, wiring – and spray foam insulation. “I call it the deconstructed home,” said James.  “People now are smarter, more educated about building and energy efficiency. They want to see what’s inside. And sales took off! It was a totally new way to sell houses. Local building inspectors liked it, too.”

The homes weren’t selling for more money, but they were selling a lot faster – and, to investors, time is money. The quicker you can recover an investment, the less financing costs you have.

By showing a “deconstructed home” rather than the usual finished showcase model, Meritage Homes has educated homebuyers on construction techniques and efficient building envelopes. This image shows a deconstructed Meritage home from one of its San Antonio developments, as shown on housingzone.com.

CEC’s focus on new construction ignores issues for remodels

Then our conversation touched on another issue with the current California energy code, and that is its almost obsessive focus on NEW construction. One goal at the CEC is for all new homes built after 2030 should be Net Zero. But remodels to existing homes also impact the energy grid, and at least in California, remodels right now represent a significant portion of current construction activity. (This is according to James – I haven’t yet found any data specifically comparing either dollars spent or number of projects of each type, in CA).

Sometimes this results in a very artificial situation when we try to show compliance for a remodeling project. It becomes an exercise in hoping that the project qualifies for prescriptive and we don’t have to run an energy model. For example, if a remodel is not adding any square footage, but the total glazing area is over 20% of the floor area, there are situations where the project just doesn’t qualify for prescriptive compliance. And let’s say that this is a low-budget project; they’re changing out the heating system and enlarging a couple of windows and leaving the rest alone, maybe it’s mainly an interior remodel which doesn’t affect the building envelope.

Well, there are times we’ve had to run a whole-building model that included all portions of the existing home that aren’t being upgraded, but which aren’t built to current energy standards. It’s easy to go down a path of adding new energy measures that not only add to the cost of the project, but which can just get ridiculous. Open more existing walls to re-insulate? You could trigger a seismic upgrade. Replace all the windows? Well, maybe the old windows were still perfectly good, why throw them away? Is that “sustainable building”? I’ve spent hours reading the Residential Compliance Manual’s sections on alterations and remodels, and sometimes writing to the CEC, to find out what’s really allowable.

QII checklists for each type of insulation didn’t include one for open-cell spray foam

James reminded me that the HERS rater has to follow different QII checklists based on which type of insulation is used in the project. So there’s one QII checklist for fiberglass batt insulation, and a different checklist to use for blown-in, etc. Here’s a nice checklist writeup from ConSol, an energy group based in Stockton.

This checklist does not affect allowable R-values used in the Title 24 performance calculations. All it does is say that insulation should be installed evenly with no air gaps, empty spots, or compression, and that wall cavities should be sealed to limit air flow through permeable insulation types. The extra credit is really a make-up because the assumption is that typical insulation installation procedures are so shoddy that substandard installations are the norm rather than the exception. So, what’s not to like about open-cell spray foam exactly? And yet, because the CEC had no official checklist that was specific to open-cell, and they didn’t want to lump open-cell and closed-cell together, the omission has led many HERS raters to conclude that low-density spray foam was simply not allowed for the QII credit. That may in fact have been the official CEC policy, too.

Some HERS raters have very extensive backgrounds in building efficiency, construction, and green building; others just don’t have the same depth of knowledge. That’s one reason we chose to list some HERS raters on Green Compliance Plus who we felt had a better grasp of the underlying principles behind Title 24 energy compliance. Our HERS rater affiliates are people with multiple credentials: some are HERS and GreenPoint Raters, some also have CEPE certification, and most have other creds ranging from Energy Star to BPI to LEED for Homes. They already have experience working with integrated project teams on custom home projects, and are more proactive about anticipating potential situations ahead of time or recommending solutions instead of just showing up for the inspection and saying, “Well, you fail, and there’s nothing I can do to help. You won’t get your rebate after all. ‘Bye, now.”

The CEC doesn’t always realize these ramifications until they’re pointed out

On the above mentioned NSHP case study, when James brought this up to the CEC staff and engineers, they were appalled. They had never dreamed that their policies would ever lead to a situation like this. The HERS rater had said, rather erroneously, “This product doesn’t work. Therefore, it’s not allowed.” What he really should have said was, “This product doesn’t have an authorized CEC checklist. And it’s still not allowed.”

Checks and balances to prevent cheating are well intentioned, but they can really gum up the works

“The CEC really wants to discourage cheating,” said James. There are certainly more steps to verification now than in the 2005 code. The whole CalCERTS registry process, with online filing of  the tandem forms for the Title 24 energy compliance report, the installation certificates, and then the HERS certificates, is a great idea but a royal pain in the bum. The online workflow is especially agonizing for custom remodel projects. The CalCERTS support folks are very nice and they also have to follow a ton of regulations that attempt to cover every possible home construction scenario; they’ve never had to consider a different workflow for custom homes where an architect is directly involved.

The code update process is complex and unforgiving, not unlike San Francisco’s planning and approvals process.

So – what if someone wants to advocate for, say, a better attention to remodels, or to custom architect-designed homes? You’d better have a full-time staff person on the job. “The process is so cumbersome, with hearings, submittals, and a lot of 45-day language,” said James. (Really it’s just like the SF planning process) “It’s really arcane – miss something and you’re dead.”

Other industries have their own issues to push for in the energy code. “HVAC, energy consultants, builders… there are a few people who practically sleep in their cars down at the SMUD building in Sacramento.”

It helps to establish a good rapport with the CEC staff, who got high marks from James for dedication and responsiveness. “If you know the system really well, you can know which events are important, but you can’t tell just by looking at the CEC site. It’s a labyrinth, and you need a guide. Try to have a relationship with the CEC staff. They can help you get your voice heard.”

Is the Net Zero goal realistic and achievable by 2030?

James thinks that the goal of having all new homes built in California after 2030 be Net Zero Energy is unrealistic, and not the best way to reduce overall building energy use statewide. “NZE should be affordable to more people than it is right now. We should be making it easier for people to comply even as we tighten the standards. It would be better to reduce energy consumption by 40-50% rather than try for some exotic concept like Net Zero. Go for more basic stuff – air sealing, HVAC sizing, more credit for unventilated roof assemblies.”

“Net Zero Energy is a great idea,” he continued. “But in the construction industry, there are so many different kinds of people involved. There are builders large and small, plan checkers, building inspectors, HERS raters, architects, energy consultants… no one knows how to do it right yet when it comes to energy compliance. Right now, this education is being force-fed into the system when people aren’t ready. NZE is such a complex concept, it requires a very integrated approach. If you push it on people too fast, it’ll be a disaster in the implementation.”

I can’t argue with him there.

What’s the definition of a “living roof” exactly?

A living roof consists of a thin strata of vegetation and soil, contained within the structure of a building roof and integral to it. Similar to a natural ledge, a select variety of plant types can be grown in the strata, creating additional garden space for use or viewing. Industry definitions characterize different types of Living Roofs according to the depth of the soil strata:

Intensive: This is what we think of as roof gardens, where we have access and usable space. Soil is at least 6” deep. These gardens are intended to be viewed and used as gathering spaces and may include hardscape. They are like gardens planted at the ground level. When we do living roofs, this is more our focus than the thin-strata type as mentioned below.

Extensive: Where there is no use or access and the stratum is very thin. Soil is 1”-6” in depth, planting is treated in mass (as in sheets of succulents or grasses). These are not intended for human use. We don’t have much experience with the latter. For now, just note that the reasons for putting a living roof on a private residence might be different, more personal, than the rationale for installing one on a large corporate or public building.

There is a very good book available on living roofs called “Planting Green Roofs and Living Walls“, by Nigel Dunnett and Noel Kingsbury. Hydrotech is the living roof system we typically use, and they used to have a pretty good web site.

This image shows shallow and deep assemblies for living roofs from a single manufacturer (Carlisle).

What are some good residential examples – your favorites?

One project we did, we’ll call it the “Sky Garden” for the sake of our client’s privacy, involved very extensive roof gardens and some vertical living walls as well. Unfortunately we don’t have photos available at this time, but we can describe it a bit. The house is on a steep hillside, leaving very little usable outdoor space. There are several roof areas, all fully usable, including a fire pit, a patio, and a vegetable garden. Part of the roof is heavily shaded, and the other part gets a lot of sun; there are different plantings in each portion to take best advantage of the sun conditions.

Under the planted area, the roof itself has several drainage areas similar to what you might have in an indoor shower. A layer of foam in each drain area acts as a leveler to maintain an even 6″ soil layer throughout. Rainwater runs underneath the foam to the drainage openings. Roof vents and other mechanical features are concealed inside decorative shrouds that relate to the building materials and guardrail.

[See drawing details further down in this article.]

The most interesting part in a way is the water management, something we mentioned in our last discussion with you as well. Our “Sky Garden” project actually uses four sources of water, in a hierarchy that prioritizes water sources: first, grey water. Next, rainwater. Third, well water. Finally, if and only if all other water sources are dry, say during a drought, the roof garden can be irrigated using city water.

Here’s another recent project, a GreenPoint Rated house in Palo Alto, done in collaboration with architect Cathy Schwabe.

This roof garden designed by Cathy Schwabe and Arterra LLP is a good example of what can be done even with a very small space. The GreenPoint Rated home was designed by architect Cathy Schwabe, who notes that she and Arterra worked collaboratively on the design and detailing, with each firm taking the lead in specific areas.

Although we tend to work on projects where the roof garden is fully usable, it’s also possible to create small rooftop gardens just to add visual interest in an urban setting, especially if the view out the window would otherwise be unappealing – bare rooftops or concrete walls, for example.

What are the benefits of having a living roof? Why would you want one?

The greatest benefit of having a living roof is expanded livable and/or visual garden space. For residential design, this is typically why you would want one. There are many additional benefits that may or may not be a factor, depending on the project, program and climate.

Additional benefits can include:

• Great insulation quality for the building. Living roofs help cool the building in summer and retain warmth in winter.
• Increases longevity of the roof system, by protecting the membrane from ultra-violet light and extremes of temperature.
• Decreases heat sink effect on hot sites-most apparent on a neighborhood level, when many roofs are planted.
• Retains and slows water runoff during and after rain storms, releasing it slowly, over a prolonged period of time. This reduces risk of flash flooding in urban areas during heavy rains.
• Increases opportunity for plant life, habitat & wildlife.

Another green roof from Arterra LLP. A well-designed intensive living roof looks almost the same as ground-level landscaping.

Is there any hard data on these claims for energy savings, heat sink reductions, or comfort improvements?

Yes, but I don’t know that off the top of my head. A lot of research in Europe and Canada has been done. [In densely built-up urban settings, a certain percentage of the rooftops might need to be planted in order to achieve a noticeable change in the overall "urban heat island" effect. Even simply making more roofs light-colored instead of black tar can help.]

Can you have a living wall, too? (e.g. plain old invasive-species ivy)

Yes, there are several, naturally clinging vines. There are also structural green wall systems you can attach to a wall, which provide an armature of support for any vines to grow through. They are separate systems and structures that have different plant types, irrigation and details. There are a number of pre-made systems out there: Fyto Wall and  Tournesol VGM Modular Living Wall to name a few, plus the custom hydroponic system pioneered by Patrick Blanc. We have used both Fyto Wall and the Tournesol systems.

Living walls don't have to accommodate human foot traffic, and they can be quite elaborate. I wonder how much work it takes to keep them so neat-looking, though, and whether these walls have built-in access points on the back side, or whether the maintenance is all done via scaffolding. Left to right: Enrique Browne building in Santiago, Chile; Patrick Blanc living wall design; and a living wall design from Mingo Design.

One thing to point out is that living walls are in many ways a completely different animal from a living roof. We could probably write an entire article just about living walls. Different structures are used to hold the plants in place for a living wall than for a roof. The physics of verticality vs. horizontality affects how weight is supported, how water flows down and out, and of course plants grow upwards so they’ll look different growing on a wall than on a flat surface.

Being vertical, living walls can’t capture as much rainfall, and thus require more irrigation. Sometimes, a lot more. You wouldn’t create a living wall to save water! And they don’t help much with slowing down rain runoff, either. However, they can be a great asset in urban areas as a break from all the concrete, where space is at a premium, and you can’t expand horizontally.

Sounds like a living wall would be impossible in a desert, if they need that much watering.

It’s possible to do a living roof with succulents, but yes – a living wall, even an all-succulent one, would need too much water to be a good choice for a desert area.

When are living roofs NOT a good idea?

• On remodels where the existing structural system and waterproofing wasn’t originally designed to support the added weight of a living roof, where the structure has not been designed to take that load, and there is no budget or scope for reinforcing it. You also need a higher level of waterproofing because living roofs have a rim and might need to tolerate standing water if the drains get clogged up.

• If the roof is sloped more than 2:12 pitch. Sloping roofs are more complicated but they can be done, up to that 2:12 pitch.

• If the living roof area is only a small portion of the entire roofing area. Even for new construction, there is an economy of scale. The smaller the living roof, the less cost benefit it provides.

Drainage and overflow detail from one of Arterra LLP's living roof projects. Image courtesy of Design Ecology.

How much does it cost, as compared to a regular roof?

The range is broad. Simple seeded systems might drop down as low as $15 per SF. However something like our Marin project would be closer to $40 per SF. That includes everything except the roof membrane, which is an additional $8-$12 per SF. It can be hard to come up with a hard number for a project, because if the scope of work included extensive groundscaping and the roof garden is only one portion of that, there are economies of scale that can make it difficult to price that same roof garden as a separate entity.

What are the top things an architect should consider when adding a living roof for a home project?

• The living roof should be well integrated, correctly sized, and serve multiple purposes.
• Waterproofing is key and cannot be fudged.
• The living roof should be an element incorporated early in conceptual design. Curb and parapet detailing, structural engineering, and waterproofing are all integral to the design and the look of the overall building.

What might an architect have to do differently on a project with a living roof?

Decide sooner, rather than later. Adding a living roof later in the design process incurs a great additional cost. However, if a living roof is a possibility, it opens up so much opportunity to expand living space out and into the garden, on multiple levels throughout the home. It also provides an opportunity for an interesting visual feature, as seen from key living areas of the home that might otherwise not have an interesting view.

Parapet waterproofing detail from Arterra LLP, from one of their living roof projects. Image courtesy Design Ecology.

What sort of special consultants would you need to create a roof garden, aside from a landscape designer? What about installers?

There are manufactured systems readily available on the market today that provide all the information an installer would need. Typically a waterproofing specialist is involved, as with most roof installations today.

A landscape contractor typically installs the living roof system. They need to coordinate closely with the general contractor, the roofing subcontractor, and the waterproofing consultant, as the waterproof membrane must be covered as soon as possible after it is tested.

The division between the general contractor and landscape contractors’s scopes of work needs to be definite and clean. It’s best if the general contractor is responsible for the structural construction of the roof and the waterproofing. Then a water test can be done. When the membrane is deemed waterproof, the landscape contractor can begin installation of the layers of material, soil and plants.

This living roof example, courtesy of waterproofing experts Neumann Sloat Blanco Architects LLP, is in Marin, CA. NSB designed the waterproofing, drainage, and soil retention system.

The Neumann Sloat project is a good example of a “non-use” application, where you’re not using it as a patio, but you’re making a visual feature out of something that would otherwise just be an ordinary-looking garage roof.

How are living roofs put together? What are the major materials, components and systems?

They are basically a big bathtub, integrally built into the roof and parapet. First, the roof structure is monolithically waterproofed and heavily tested to ensure the waterproof membrane is intact. Then the pre-manufactured living roof soil system is installed. These vary slightly but they basically consist of a root barrier to keep plant roots from penetrating the roof membrane, a soft insulation layer (which protects the membrane), a drainage layer (like an egg crate), and a layer of filter fabric.

Layering of components from bottom to top are as follows:

• Roof deck (wood frame or concrete)
• Waterproofing
• Protection Board
• Drain Mat
• Geotextile/filter fabric
• Irrigation piping
• Soil
• Plants
• Mulch

Closeup of the Neumann Sloat Blanco living roof shown previously. Plantings here don't need mowing, and have mulch in between.

Along the perimeter of the building at the curb or parapet you will need:

• A curb, which must be at designed to be above the top of the soil
• Minimum 6” width of light-weight gravel between curb and soil area, separated by stainless steel edge restraint (Green Roof Solutions is one supplier)

For drainage:

• The roof deck must be sloped to drain underneath the soil layer. The roof design should include at least 2 drains that are waterproofed and hard piped out to the stormwater or rainwater catchment systems.
• The sloping of roof deck affects thickness of the soil profile above, and must be cross-checked with the project’s structural engineer.
• Lightweight foam board can make up depth difference if needed, to control weight.
• Inspection Chambers  (SS, Green Roof Solutions) will be needed at drains and irrigation valves.

Beneath a living roof is a waterproofed roof, with a rim, and adequate drainage. These stainless steel eyebolts will support a soil retention system. Image courtesy Neumann Sloat Blanco.

A specially formulated soil mixture is then brought in, the thickness of which varies. We prefer to work with a minimum of 9″ of soil, going as deep as 18″ in some situations. The medium tends to be very low in organic matter and have crushed lava or small gravel, which gives it enough heft that it won’t blow away.

Plants go in as they would in any garden although they are usually fairly small container stock. The whole thing is then mulched to secure the soil and insulate the plant roots. If hardscape elements, such as paving or decks, are required to be built over the green roof, that can be done in ways similar to how they would be installed onsite for ground-level landscaping. Hardscape features may be specially designed to minimize weight.

Hydrotech supplies most of these layers. You will pay a premium, because the pre-manufactured costs are usually higher than purchasing the same materials elsewhere. For instance, root barriers are used in ground-level landscaping and are a readily available material. However, Hydrotech requires you use all of their component layers in order to warranty their system. Some clients are willing to pay for this just for the peace of mind. However, a sound green roof system is entirely possible to achieve with products other than theirs.

A soil retention system such as this one is essential for living roofs that are on a slope. Image courtesy Neumann Sloat Blanco.

How do you decide what to plant on a living roof?

The living roof is really like a ledge planting. It’s more exposed. You have only a thin stratum of soil, with higher winds and fuller sun exposure than you might find on the ground level. Plants native to ledges and shallow soils often work well. Most grasses work very well. We design each project uniquely, according to site conditions, depth of planting soil, exposure, etc. There are a lot of resources available now to help in identifying plants that have done well on living roofs.

Another shot showing the soil retention system installed on the living roof for Neumann Sloat Blanco's Marin project. A copper parapet cap provides UV and physical protection for the single-ply membrane underneath. It is also more attractive than leaving the membrane exposed. Image courtesy Neumann Sloat Blanco.

Are living roofs heavy? Do you need structural reinforcement?

Yes, absolutely – especially if you’re going to be walking and sitting out there. They are engineered to assume that the drainage may fail and the whole “bath tub” could then fill up with water. The engineering design must be integrated into the overall design for the structure to take this potential condition into account.

What about retrofits or remodels?

It’s possible, depending on engineering. If the retrofit/remodel is being re-engineered anyway, it is a good possibility.

Do living roof projects ever run up against permitting issues or local building codes? There’s no special credit for them in the California energy-efficiency code, I know that, although green building codes such as CALGreen and BuildItGreen’s GreenPoint Rated system do recognize green roofs to some extent.

Building codes always apply, but we have not run up against anything unusual. If the living roof is accessible, it will need to meet codes for guardrails, etc. There are some LEED and BuildItGreen credits for living roofs, depending on multiple factors.

There are some fire departments that have a say on the plant materials used on living roofs. They review the planting as they would a ground-level landscape. Certain fire-prone plants are prohibited. If local fire codes specify highly fire-resistant roofing materials, they will probably be concerned that plant material should be fireproof as well. On one of our projects, the fire department also required that there be a walkable perimeter around the roof in case firefighters needed roof access during an actual emergency.

Here's another living roof in progress series, this one from Arterra LLP. First comes the framing of the roof and parapet.

What about waterproofing?

The waterproofing makes or breaks these systems, and there is simply no cheating this one. The waterproofing must be a monolithic membrane or there will be problems. That said, the technologies available now for waterproof systems are incredible. Hydrotech seems to be an industry leader. They provide several types of membranes as well and the component layers (including soil). Again, you have to use all of their components in order to get their warranty.

Arterra LLP living roof construction series, part 2: waterproofing layer. The waterproofing is the single most important thing to get right on a living roof. No cheating, no fudging, no shortcuts.

What about maintenance? Do owners need to hire a special service?

The garden needs to be irrigated, fertilized and maintained, as with any garden. Drains need to be serviced as with any roof drain. It is a man-made environment, just like any other landscape. But, roof gardens are more sensitive than gardens created on the ground in full-depth soil. While they may not take more man-hours to maintain than ground-level plantings, living roofs do require more frequent monitoring. Getting the irrigation dialed in correctly takes a bit of attention while the plants are growing in. Over time, they will require less time and be on a par with maintenance for ground-based plantings.

Arterra LLP living roof construction series, part 3: plant layout.

How do you keep a living roof healthy?

If you have planted the right plants and set the right irrigation, they will only need periodic fertilization and regular garden maintenance to stay healthy.

What about weather damage?

This can be a factor, of course. All conditions are more severe on a roof, and damage can occur. Wind is probably the greatest concern and affects the plant choices made.

How easy is it to add greywater irrigation?

Technically, it is easy. Building code sees it differently, though, and at this point I doubt you could get this approved in California. If you did, there would be some concern with a buildup of salts in the soil, so at best it would have to be a dual system, to ensure that you could periodically flush out the salts.

This New York City rooftop garden has quite a mix of plantings, including a small patio, flowers, what might be an herb garden, and even some sizable trees.

Are grey water and rainwater systems the same thing?

No! Grey water and rainwater catchment are two completely different things. Grey water is from household use: laundry, showers, and bathroom sinks. You can’t really store it long-term in a big cistern because it’s not as clean as, say, well water. Too many organisms can “bloom” in grey water. The way to think about grey water is that it’s continually replenished. You can use it right away, or same day, for landscape irrigation. If you have a household with a lot of kids, and a lot of laundry, you might generate a significant amount of grey water to make this worthwhile.

Rainwater catchment systems are an attractive idea but they can be expensive. You need a lot of storage tanks. Rainwater storage might cost around $1.50-$2.00 per gallon. Depending on your garden’s water needs, you could be spending tens of thousands of dollars just for the storage tanks.

Tell me more about water budgets. I assume you’d start by factoring in the average annual rainfall.

Yes, that is where you start, but then you have to identify supplemental water sources in case of a shortfall. It’s also dependent on the plantings, the area, and how shaded the roof area is. We do detailed water budgets as part of all our design projects.

Is a living roof just like having another lawn?

It can be, if you plant grass and mow it. All the accompanying maintenance of having a lawn would apply: heavy irrigation, weekly mowing, heavy fertilization and weeding. We don’t recommend it. Most of our plantings are not lawns. If we do incorporate grasses, they are no-mow natives or ornamental grasses.

Japanese architect Terunobu Fujimori has done some intriguing-looking designs that integrate living plants with slate finished walls. I don't know how water-intensive or maintainable they are, but Fujimori is using vegetation as an artistic medium in a way that preserves some of the cleaner lines in the design.

Can you put a living roof in any climate? What would you do different in Tahoe than in Livermore?

Yes, you can have one in any climate. Living roofs have been used extensively and for many years throughout Europe and Canada, so winter climates are fine. We don’t have much experience designing systems for northern climates, so we don’t know how they handle the snow load. We’d guess that it is mainly an engineering question. The main difference would be the plant choices, as those climates are so different.

Are there other design features that could interfere with a living roof? Certain types of roofing assemblies, tilted roofs, skylights, solar panels, vents, mechanical on the roof, etc.

Yes – all of these can interfere with or modify the design of a living roof. All of these factors should be considered as a whole in the early phases of design. Roof vents can be concealed, of course – solar panels would have to fight for space. And, local fire departments may require a walkable perimeter on a roof, which would also take away space from either gardens or solar arrays.

Some of the DIY living roofs look very untidy. I can’t imagine putting them on a Modern house.

Yes, they can be. That’s the old “hippie” look. We can design water-wise gardens that have a very sophisticated look, but don’t require a lot of water. Each living roof is designed to be in character with the rest of the project.

This images is from a web site promoting "Earth Houses" and it's got a sort of untidy, disheveled charm about it. It's probably not the look you'd want for a very minimal, Modern home design. However, it'll help more with slowing rainwater runoff than a very thin, close-mown piece of turf.

How do surrounding shade trees affect living roof design?

If you are fortunate enough to have mature trees high enough to shade the roof, it is a blessing. Shade is great. Typically, there is more of an effect from surrounding buildings casting shade or creating erratic wind patterns. Our “Sky Garden” project had shade from redwoods on once side and bright sun on the rest. It was designed like any other landscape: shade-tolerant plants on the side shaded by the trees, and drought-tolerant sun plants in the open areas.

Are there any cautionary tales worth mentioning?

Our experiences have been very positive. This is a wonderful way to expand livable and visually attractive space in tight urban settings and on properties with limited buildable space on the ground plane. Steep hillside sites are always looking for more area to create flat outdoor spaces, regardless of of the size of the lot.

The 5,000 year old monument of Newgrange in Ireland is a very early example of a "sod roof" with a multi-layered stone construction beneath.

This article explains how to assess water heater efficiency numbers, including the use of a handy lookup database at the California Energy Center’s web site.

California energy compliance calculation shows separate scoring for three main energy areas: heating, cooling, and water heating. A proposed design, here for a custom single-family home, can be behind on both heating and cooling and still make it up with a high-efficiency water heater.

Why’s water heating so important all of a sudden?

Well… if if a project is behind on heating AND cooling, and it’s already maxed out every other trade-off measure, it can sometimes be salvaged by running it with a more efficient water heater, specifically, a tankless. You’ll really feel the pinch if your project needs to exceed Title 24 by 15% or more. This is a basic requirement for almost all of the “beyond compliance” green standards: GreenPoint Rated, CALGreen optional tiers, LEED for Homes, and incentive programs such as the New Solar Homes Partnership. Local California jurisdictions are adopting various forms of these optional tiers, in some cases requiring very high GreenPoint Rated scores for larger homes.

“The equipment you see with values above about 90% are condensing equipment that have great efficiency values but need different installation practices and cost a bunch more,” warns Ken Nittler, creator of the Micropas Title 24 energy modeling software. “The most common equipment we see are small storage water heaters with energy factors of 0.60 or 0.62. On tankless, we see energy factors of 0.82 or so. On tankless condensing units, we see 0.94 energy factors.”

General Compliance Notes

Radiant Heating. Some basic questions that affect water heaters in Title 24 have to do with the heating system: specifically, whether radiant heat is under consideration. When you run a Title 24 calc with radiant heat as the specified heating type, the water heater drives both the Heating and the Water Heating portions of the score. The Heat score is sensitive to the water heater’s Recovery Efficiency, while Water Heating is associated with the water heater’s Energy Factor.

Solar Hot Water. There’s a very substantial credit for solar hot water in Title 24. You’ll need to know the “insolation fraction” which is the portion of total hot water that you expect to receive from solar thermal. A realistic number may be 25-50%, but that depends on how much sunshine the house will actually receive based on weather, site configuration, surrounding buildings and landforms, house footprint and available space for solar thermal panels, shade trees, and the like. Plan on having a supplemental unit such as an indirect storage tank or an additional water heater, since you’ll need hot water at night as well as during the day.

Radiant + Solar Hot Water Combined. If you’re going for radiant and/or solar hot water, you’ll need a mechanical consultant with strong knowledge of the differences among different manufacturers and unit types. For one thing, radiant heating water temperatures may be different from what you’d need for domestic hot water, so if you’re running them off the same unit or the same tank, specialized installation or components may be needed.

No Electric Water Heaters, Please! Fuel source, such as whether the water heater is gas-fired or electric, has a big impact on Title 24 compliance. Even for all-solar homes. There’s a huge penalty for electric resistance – that’s all you need to know for today’s discussion.

What’s the Highest Efficiency Realistically? The technology inside the water heater, such as whether it’s a two-stage condensing system or a hybrid, can have an indirect impact on Title 24 compliance. Sometimes if something’s not passing I’ll just test some of these numbers to see what happens, but eventually the numbers have to be realistic. This is where I asked around a bit to make sure that a water heater with a .95 efficiency was a real animal. It is – for a tankless. Condensing boilers also can have efficiencies as high as .95. There may also be condensing storage water heaters available, probably at a high premium.

Tankless or instant water heaters typically offer higher efficiencies, and thus are an advantage for demonstrating California energy compliance. Their real-world efficiency depends on other factors such as their proximity to the point of use.

Installation Issues. Do yourself a favor and check with your builder and subs before specifying some of the high-efficiency condensing water heaters. “The equipment you see with values above about 90% are condensing equipment that have great efficiency values but need different installation practices and cost a bunch more,” notes Ken Nittler.

Types of Water Heaters

Water Heater vs. Boiler. What’s the difference between a water heater and a boiler?

• Water heaters cost less and operate at a lower temperature. The “small” version, more typically used for small to medium sized residential dwellings, has an input under 75,000 Btu/hour. Large water heaters have an input that is over 75,000 Btu/hour.

• Boilers make scalding hot water, and more of it, typically around 200 degrees Fahrenheit. That’s why it’s called a “boiler”. A boiler is primarily intended for space heating (radiators), rather than making hot water for daily use. However, boilers are less adaptable to making hot water at lower temperatures at the 120 degrees for showers or 120-135 degrees for radiant flooring.

• They use different efficiency measures, and this last point is what’s crucial for Title 24 compliance.

Indirect Storage Tank. This is a separate, insulated storage tank with a heating element that can be used to collect and store hot water from an intermittent source such as solar thermal. It doesn’t actually heat the water up, it just keeps it hot after it’s already warmed by some other means.

Energy Compliance Calculations – Inputs Needed

Title 24 Defaults. About 90% of the time, we run our Title 24 projects using the software program’s built-in default, which is a small storage water heater with an energy factor of .60. This is a safely conservative assumption, since you can only go upwards from here. Within the Title 24 software, it’s the efficiency that seems to matter, rather than the number of units installed. In reality, however, larger homes are likely to have a boiler, or perhaps several different units at different locations.

Example of one of the pre-created sample inputs for the Micropas Title 24 compliance software. The values used here are specific to the water heater product specified, and they can influence whether or not a project meets compliance standards or not.

Efficiency Measures. Although the array of water heating technologies seem to be almost endless, the only thing that matters for energy compliance are these efficiency ratings, and they’re different depending on whether it’s a water heater or a boiler, whether it’s hooked up to a radiant heating system, and for water heaters the Btu input. There’s some confusion of terms here; I’m sticking to the terms as they are used in the Micropas software inputs.

Energy Factor. Used for “small” water heaters under 75,000 Btu/hour. The energy factor (EF) indicates a water heater’s overall energy efficiency based on the amount of hot water produced per unit of fuel consumed over a typical day. It’s a sort of umbrella measure that includes the recovery efficiency and standby loss measures described below, and is expressed as a decimal fraction between 0 and 1. An EF of .60 is average, while one of .80 will yield noticeable improvement in a project’s Title 24 compliance score.

Recovery Efficiency (sometimes called Thermal Efficiency, or AFUE, although they’re not exactly the same thing). Recovery efficiency is for “large” water heaters and boilers that are 75,000 Btu/hour or above. This is a measure of how effectively the unit turns fuel into heat. It is measured as a fraction between 0 and 1, higher being better. This seems to affect compliance score when radiant or hydronic heat is the main heating system.

Miles Hancock says, “Thermal efficiency is a useless number, measuring the unit’s efficiency at boiling water… what’s key is keeping that water hot, which is the standby loss. Standby loss is what kills the energy compliance.”

Standby Loss. Used only for “large” water heaters with a storage tank, this is the percentage of heat loss per hour from the stored water compared to the heat content of the water. In other words, once the water’s hot, how long does it STAY hot? This is measured as a fraction as well, in this case lower being better. The software built-in for the sample large water heater shows a standby loss of 0.03. Miles

Internal and External Insulation R-Value. Used for indirect storage tanks only. I haven’t tested the effect that this would have on residential compliance, because indirect storage tanks aren’t as common a configuration for the custom home projects that we analyze.

One thing that doesn't affect energy compliance is the style of the faucet - only what's behind it.

Other Inputs. There are additional inputs for heating element type (gas, electric, heat pump), rated input for gas heaters in Btu/hour, storage tank volume in gallons, distribution type, and for some types of water heaters, pilot light size in Btu/hour. For almost all our projects, the fuel type is always gas, since electric water heaters are discouraged.

The distribution type has to do with the piping configuration, and that’s mainly for larger residential projects. Example values are “standard” (the default), “Point of use”, or various recirculating on-demand varieties. I’ve occasionally run projects with these different distribution types to see what difference it made, and for a typical 4,000 SF single-family residential house, it made almost no difference in the compliance score. Sometimes it can make a big difference in the real world, though, so if you or your client are trying to maximize actual energy efficiency, as opposed to just complying with Title 24, try reading up on it in Ann Edminster’s book “Energy Free”.

Heater/Boiler Systems in the Title 24 Software Model. This is based on Micropas, which is one of two programs you can use for California energy compliance. I haven’t used Energy Pro as much, and it’s organized a bit differently. Here are a few basic types of heater/boiler systems that are set up as default or example entries in Micropas (and why you would pick one or the other):

• Small Storage. 40,000 Btu, 50 gallons, 0.60 EF. Use for legacy systems or if you don’t know what else to specify, and you want to assume the lowest allowable efficiency for the time being.
• Large Storage. 100,000 Btu, 100 gallons, 0.77 RE, Standby loss 0.03. Realistically this would be used for a larger home. However, I have noticed that specifying a large storage as opposed to small one lowers the compliance rating, probably because of the higher input rating.
• Tankless (instant). 195,000 Btu, EF .80, RE .76. This is the equivalent to a small storage water heater, and would be used in comparable applications such as a single family home as a more energy-efficient alternative. Compliance advantage is that it’ll boost the water heating portion of the score by as much as 30%, and it’s often a good choice in the real world as well. Real-world advantages: higher efficiency, theoretically endless hot water supply, smaller footprint. Real-world disadvantages: must be located close to point of delivery in order to realize energy savings.
• Boiler. 250,000 Btu, RE .80.
• Instantaneous boiler. 250,000 Btu, RE .80. Same as a boiler, but without a storage tank.
• Electric Storage. This is an electric resistance water heater. You will never, ever, want to use this type when using the performance method of compliance. Occasionally, if you’re trying to grandfather in some unpermitted basement addition, guest cottage, or in-law unit, and the space qualifies for prescriptive (not too much glazing!) you might be able to get away with stating “existing systems to remain” and bypass the issue. But that’s about it.
• Electric Heat Pump. I’ve never had to model this type of water heater, so I can’t speak to it. I don’t think the penalty is as steep for this type as for the electric storage.

Hot Water for Additions. If we run an addition as “Addition Alone”, water heating is not calculated. However, if the addition won’t pass by itself and we have to model the whole house, then the water heater becomes a potential source of energy trade-off. It’s even more important for additions and partial remodels, because other interventions such as upping all the wall insulation may not be available with projects of limited scope.

Pools and Spas. These are not included in the energy report calculations. There are separate energy standards that apply to them. For now, they are outside the scope of this article.

A Nifty Search Lookup for Current Models

Miles Hancock, one of our Green Compliance Plus Affiliates, walked me through the Appliance Efficiency search database on the California Energy Center’s web site. This database contains listings for all appliances certified to the California Energy Commission as meeting currently applicable efficiency standards – so it won’t be of much use for legacy systems (for remodels or additions). Some of the terms they use for efficiency are different from what’s described in the preceding article, but I’ve tried to list their equivalents above, where possible.

The California Energy Center's Appliance Efficiency search database lets you find the rated efficiencies of all models that meet current energy standards.

And now, a new requirement, or really an old one that’s just now being enforced: All CF-1R reports that call for a HERS test must be officially “registered”. Don’t say we didn’t warn you. Plan checkers are starting to kick back custom residential submittals if they don’t see a CalCERTS watermark on the energy report.

But first, a little background.

Our clients are other design-oriented (read: “modern”) architects. Some of them like to use dramatic walls of glazing in their designs. This, while awesome, presents an energy problem, because glass is a poor insulator compared to, say, a 2×6 framed wall cavity packed with high-performing insulation. California’s energy code seeks to discourage over-glazing by imposing a maximum glazing threshold at 20% of the conditioned floor area.

The Title 24 prescriptive energy report, showing where various HERS tests can be called out. This example is the CF-1R-ADD form for Additions. Title 24 is a reference to California's energy code.

The only way around this is to employ a complex “performance approach” to energy compliance, whereby the project is run through energy modeling software that allows trade-offs – acres of picture windows in exchange for beyond-code energy upgrades elsewhere. As long as the house as a whole is under the threshold for energy usage, the designer can creatively determine how that goal is achieved.

For the performance method of Title 24 energy compliance, the energy modeling software shows whether HERS tests are required on the report's summary page. This example output is from Micropas, a software package that is one of only two authorized packages for demonstrating California energy compliance. As you can see, the project is barely passing even with the additional HERS credit.

For Those Who Came In Late

What are HERS tests?

HERS stands for Home Energy Rating System, a method of diagnostic analysis to determine a home’s energy efficiency by establishing a benchmark and then making site-specific upgrade recommendations for the homeowner. It’s not specific to California; other state energy codes sometimes reference HERS as a standard or its later incarnation, HERS II. HERS raters are independent contractors who are trained and certified through an organization such as CalCERTS.

Why does California’s energy code include HERS testing?

HERS is a recognized and proven standard that relies on empirical testing on a case-by-case basis. Many of the HERS tests address well-known construction deficiencies that can waste up to 30% of a home’s total energy consumption. With a goal of having all new homes statewide be Net Zero by 2030, the State of California has employed a phased approach that tightens the energy code in three-year increments.

When does California require HERS testing?

Depends which energy compliance method you use. Prescriptive requires certain tests, like the duct blaster test, for any new construction or any time a forced-air system is replaced. Performance has this as an option, because it boosts the score quite substantially.

What is this magic database up in the sky, and why haven’t I heard of it before?

Actually, you have if you’ve been reading our blog. But, if you read our blog, chances are your’e the last group of architects to be affected by it. Back in 2009 I took a CABEC-sponsored Title 24 class in Sacramento on upcoming code chances. However, at that time nothing had been implemented, and no one knew how it would actually work.

Since then, CalCERTS has been working with the California Energy Commission to get this up and running. It’s been gradually phased in for different types of projects: mainly production homes, which are far more numerous than the custom, one-off projects and remodels that comprise our own design focus.

The CalCERTS online registry tracks the CF-1R energy compliance reports that require HERS testing. This example is for a residential project.

As an aside, I found the CalCERTS online registry to be very fast, with no glitches – the test project I did in order to write up this article worked just fine. The registry actually parses the report file (a special un-readable ZIP file generated by the energy modeling software) so it “knows” what the project requirements are. The CalCERTS folks themselves were very courteous, helpful, and responsive. I was very impressed that the entire online interface was implemented by one person, who seems to have taken every last aspect of the energy compliance process into account. There oughta be a medal for that!

Why do we need a database? Isn’t there enough red tape as it is?

The idea behind the registry is to reduce cheating. Prior to this, any CF-1R requiring a HERS test had no follow-up to ensure that the test was actually performed, or that the project actually passed the test.

To discourage cheating, CalCERTS registry requires a special output file. It then creates a readable PDF file with the CalCERTS "watermark" applied behind. It also adds a footer to the report with a registration number. This example shows how the watermark is applied to an energy performance report.

So, Who Does What?

Here’s a magic molecule diagram that shows the “new” process highlighted.

Custom residential projects that require HERS testing must now register online with CalCERTS to show compliance with California's energy code.

Green Compliance Plus clients: We take care of pretty much everything that’s in the shaded box. The only thing you’ll need to do is make sure that if your Title 24 energy report calls for any HERS tests, you’ll need the watermarked version on your submittal package.

Note that this diagram only goes up to permitting – there’s a Part II that shows how all the installation certificates and HERS test results are uploaded later down the road. For now, suffice it to say that whatever’s in that energy report has to be followed in the field, because if something doesn’t match up, chances are either the HERS rater or the building inspector will pick up on it.

Impact of Design Changes and Field Swaps

All this bureaucracy means that any changes to the design, including field swaps, could mean having to re-do the energy compliance report and a whole slew of headaches for architect, builder, and owner alike. The energy-modeling “performance” method that we use most of the time allows you to specify the exact efficiencies of every piece of heating equipment and every single window. This allows for a lot of flexibility but it also locks you in to using products that meet those numbers – and are field labeled as such.

Here are just a few of the changes that could trigger a new round of energy analysis: changes to unit models for heating, cooling, or water heating equipment, especially efficiency; any change to the building envelope, including wall and roof assemblies; moving to a less efficient window product; failing a required HERS test; local building requirements that mandate exceeding Title 24 by a specified percentage.

Re-doing the energy report means you try to make up the shortfall somewhere else. This gets harder to do the further along the project is in construction. If you get caught during a site inspection, the damage control can eat up the project budget, not to mention irritating YOUR clients – the homeowners who rely on you, the architect, to guide the project smoothly to completion.

Don’t paint yourself into a corner. Make sure that your builder and all the builder’s subs REALLY understand what’s on that energy report.

All This Applies to Remodels, Too

Even alterations, additions, and other remodeling efforts within the State of California may be subject to this CalCERTS registry requirement. Oftentimes, these are our toughest energy compliance projects, because the scope is limited but for one reason or another we can’t use the simpler prescriptive approach. Usually it’s because the project is over the glazing limit. However, we don’t have much room for energy trade-offs using the energy model because most of the house isn’t being opened or altered.

(Home shown above is designed by Sparano + Moody Architecture, and has earned LEED Silver certification. But LEED homes don’t all have to be in the wilderness, either.)

The Questionnaire

I took a straw poll amongst our design colleagues, one of our GreenPoint Rater affiliates, and also reached out to a few people that we don’t know – architects, builders, and developers – who’ve completed LEED-certified private homes in California. The questions were, more or less:

• Was it worth the effort?
• What did YOU get out of it?
• Did it add value to the property?
• How much did the rating process itself cost?
• What other additional costs were incurred?
• What can architects, builders, and homeowners do to make the LEED process go more smoothly?

We also discussed the relative merits of LEED vs GreenPoint Rated for private homes in California, including when to go for one vs. the other.

The Respondents

Numerous people took the time to share their opinions freely. In no particular order:

• Rob Lehman of Green Score Solutions. Rob has multiple credentials as a GreenPoint Rater, a HERS rater, and LEED AP, and he’s listed on our Green Compliance Plus affiliates page.

• Rich Williams of ArtHaus, LLC, a residential development company near San Diego. ArtHaus specializes in building sustainable high-end modern homes, and their goal is for all their projects to obtain LEED certification.

• Jonathan Feldman of Feldman Architecture. We’ve known Jonathan for years through the Small Firms Committee – he’s completed or is working on six LEED Platinum and two LEED Gold custom residences. He is a strong proponent of the LEED system.

• Dan Johnson of Arkin Tilt, a well-down Berkeley firm that is in the vanguard of sustainable residential design.

• Eco-Struction, a green builder in Ben Lomond, CA near Santa Cruz.

• Ann V. Edminster, home energy/green building consultant and author of the book “Energy Free” which we reviewed a few months back. She didn’t actually comment for this article, but she’s consulted extensively on LEED projects large and small, including helping design teams set priorities, analyze financial impacts, conduct contractor briefings, and prepare LEED compliance documentation. If you’re looking for a feasibility analysis to help decide whether or not to go for LEED, she might be a good place to start.

LEED and the Building Industry

It’s not just architects who care about it. Builders, developers, homeowners, and home energy consultants all have their own perspectives. Half of the private residences listed as LEED Platinum in California seemed to be credited to developers, builders, or design/build firms rather than architects. However, the majority of the LEED Platinum certified projects were large-scale enterprises like the California Academy of Sciences, multifamily housing, or public buildings – not private residences.

Developers Can Have Ideals, Too

Developers and production builders in general have a public image that seems to view them all as solely focused on making a quick buck. If there weren’t mandatory inspections and statewide energy codes like Title 24, the argument goes, they’d cut every corner, slap the homes together as fast as they can, and get the heck out before the homes started falling over. And if there weren’t environmental protections in place, these same profits-before-people villains would pave over every national park and fill them up with cheap condominiums.

Well, it seems that there’s more variety among people calling themselves “developers” than the stereotypes would suggest. I was surprised to see that around half of the LEED Platinum Homes in California were credited to either developers or design/build firms (developers who turn out a few homes at a time). And not all developers focus on tract homes, either.

One of our own projects from Mark English Architects, the Pepper Drive residence, is a GreenPoint Rated spec home built by a developer that earned a score of 113. Photo: Norma Lopez Molina

Project Scale is a Determinant

“LEED was developed more for production builders than for one-off projects. For one-off projects, GreenPoint Rating is more user-friendly and adaptable,” says Rich Williams of ArtHaus. “However, LEED certification confers a certain amount of prestige, and it’s got more brand awareness than, say GreenPoint Rating. A LEED Platinum certification means it’s the best you can get,” he continued. “A GreenPoint score of 220 is a great score, but people don’t really know what that means yet.”

This new home from residential developer ArtHaus is LEED Platinum certified. Their goal is to have every home they do be LEED certified. Photo: Ramona d'Viola - Ilumus Photography

It’s not just scale, but scope that’s important. LEED for Homes has some prerequisites that may involve a total gut rehab – opening and inspecting every wall and ceiling cavity. So you’d better already have planned on doing a thorough job on any remodel – including a thorough review of any existing HVAC and water heating systems. At least with a home that’s new from the ground up, there are no legacy components to worry about.

Sufficient scope also implies that there is sufficient budget: not only for the measures, but for the certification fees and the extra paperwork. I wasn’t able to get anyone to commit to a dollar amount for the owner’s construction budget as some sort of threshold to determine if LEED would be worthwhile on a particular project. But, the owner and architect should be prepared for upgrades to products, materials, components, systems, and installation procedures where needed to meet requirements – including baselines for energy efficiency. It’s not always something you can tack on later, either – you can insulate now, but even if the insulation is inspected during construction while the walls are open, if it’s not inspected by a LEED certified “Green Rater” – then you may not be able to claim the credit.

Why Did You Choose LEED?

Jonathan Feldman is one residential architect who’s worked on several LEED certified homes, including the award-winning Caterpillar House, a Carmel residence. Based on my conversation with him, the benefits he sees in LEED are:

• A structured and rigorous process
• Verified materials and products
• Tested and calibrated performance
• Process that is raising public awareness

“On our first LEED project, the client came to us very committed to sustainability. She felt that it was reckless the way the building industry largely ignores the devastating impact that it has on our environment,” said Jonathan Feldman of Feldman Architecture. “We were forced to take a wider and more thorough look at different areas of sustainable design, and LEED forced us to follow through with our early project commitments, and also to keep our clients, vendors, and builders committed. We received considerable goodwill from building departments, homeowners associations, and from the press because our project was the first LEED Platinum project in the area. The owners got a house where all the materials, products, and environmental strategies were more carefully considered, specified, installed, calibrated, and tested.”

The Caterpillar House by Feldman Architecture is LEED Platinum certified. Photo: Joe Fletcher

Quality control is an emphasis shared by both GreenPoints and LEED – in fact, any green building standard has to consider both construction quality and overall durability. What’s the point in building something that’s going to be torn down in a few years? Better to build it right the first time, and make it something worth keeping around.

Feldman warned that there was a steep learning curve on his first LEED project, but feels that it’s worth it – if it leads to a much-needed sea change in the building industry. “The more architects and builders go through the process, the easier it becomes. I also think that the more architects and builders share what they learn with each other, the easier it will be for all of us. There are those who don’t want to share what they’ve learned with those whom they view as their competition. I find this amazing. If we are truly concerned with making a dent in curbing the devastating effects of the building industry, then we really should be doing everything we can to help every building project move towards greater sustainability.”

Rich Williams from ArtHaus does it out of personal conviction. “LEED for Homes is a goal that I set for myself. I build stuff that I would want to live in. And with a spec home, LEED certification is a recognition of a benchmark. The biggest take-away from my experience building LEED and GreenPoint Rated homes is that we aren’t really ‘building green’, we are really building to a much higher standard of quality. Consumers will know, because of third-party verification, that the home that they will be living in should be more durable, should require less maintenance, should cost them a lot less to operate, should be more comfortable for them to live in, and (the most important one) should be WAY healthier to live in than other homes that are not being built to these standards. As the Mastercard commercials say, that last one is ‘priceless’. You folks understand how to build a better home, but a lot of folks out there don’t, so having these rating systems in place to provide guidance for doing so is extremely valuable, in my estimation.”

The value of having a structured process with some rigor to it was emphasized by several respondents, as a benefit to both GreenPoints and LEED. LEED might be considered as the stricter of the two, because unlike GPR, the bar to initial certification is a lot higher. Even an “average” home can get a GreenPoint score of 75 without too much effort, but to be LEED certified the home must meet a much larger list of mandatory measures.

Incentives

Rob Lehman reminded me that GreenPoint Rated homes are eligible for additional incentives under California rebate programs such as the New Solar Homes Partnership and California Advanced Homes. If the home is a total gut rehab with all new systems, it may qualify for these programs as “new construction”. So if the client is already thinking about going solar, the rebates can be substantial – and they’re bigger if the home is GreenPoint Rated.

So does that mean that NSHP and CAH ignore LEED certified homes? Not at all. California Advanced Homes rewards it, at least.

• In CAH, there’s a 10% bonus for “Green Home Certification” by a “recognized green building program” and there’s a 15% bonus if the home is 10% smaller than the LEED for Homes size threshold. Yep, LEED has something called Home Size Adjuster which penalizes larger homes.

• NSHP doesn’t appear to reference any green building certifications, although it does mandate energy efficiency. Why? My guess: NSHP is solely about solar power, and reducing home energy use has a direct impact on the PV system size, whereas using low-VOC materials has no impact on the solar array. Both programs use Title 24 as a yardstick – you have to beat Title 24 by 15% or more.

How Much Does LEED for Homes Cost to Do?

How much does it cost? GreenPoint Rating fees seem to be lower than those LEED certification, although I don’t have hard data to do a good fee comparison. Here are a few price points:

• Word of mouth on the street is that it costs $15,000 to get a private residential project LEED certified.

• Rich Williams quoted a fee of $5,000 for getting a 3,000 SF home LEED certified – that’s what it’s costing him – he didn’t include construction costs, though.

• Jonathan Feldman was a bit more specific: estimated rating cost of $5,000 – $10,000 in fees, required advisors, and testers, and another $8,000 – $12,000 for construction practices, materials, research, and design time. “Less in the cases where the clients manage the process themselves,” he added.

Cost analysis can be tricky, because some of it might be things you were planning to do anyway. And with something like LEED, which references other building standards such as Energy Star and (in California) Title 24 energy compliance, assigning weighted costs to requirements can be difficult. Some costs could be incurred during the energy analysis, which is required by both GreenPoints and LEED. In California, projects must exceed Title 24 energy efficiency standards by 15% or more. And, sometimes to get this, a particular project might need upgraded windows, more insulation, higher efficiency systems, or other measures. If you weren’t planning to do these things before, then yes – they’re additional. If you’re just going for the label, that might not be a good reason by itself to go for LEED – or any green certification beyond what local building authorities may require.

“Don’t do it just for the label,” warns Jonathan Feldman. “It’s asinine to jump through that many hoops just for a label. Do the measures because you were going to do them anyway.”

Commercial projects can cost a lot more. Rob Lehman mentioned a LEED certified multifamily project in San Jose with 90 units that cost $90,000 for the LEED certification! “There aren’t that many LEED Green Raters available and they’re expensive,” he noted. I don’t know how this broke out – I’m guessing it likely included the rating, the documentation, and the additional construction costs all rolled into one. And, for a large project like that, having the entire building LEED certified could boost sales and/or rental rates, “especially in certain areas,” he noted.

Does It Add Value to the Property?

Does LEED certification add value to the home? Depending on how you define “value”, here are a few possible definitions:

• A premium that homebuyers are willing to pay, as demonstrated by home sale data
• What realtors and listing services believe are the features that people care about
• What lenders are willing to finance when doing their value assessments of a sale property
• Something that brings the homeowner long-lasting satisfaction, comfort, and enjoyment

The problem is, we don’t really know how much value green building adds to single-family residences, because home listings don’t track green certifications of any kind. So, if a home sells for more, or sells faster, how do we even know whether “green” had anything to do with it? And how can we compare the value of a GreenPoint Rated home vs. a LEED certified one vs. an unrated home that nonetheless has the same green features as a rated one? Thus, data is anecdotal at best.

It seems that the general public is a lot more savvy about Blue Book car values than they are about their own homes. To the extent that they think about it at all, they’re likely to go for spot fixes based on a one-size-fits-all rumor like “I hear that radiant barriers are cool” instead of taking a wholistic approach. A minority of homeowners are DIY energy nerds, who cheerfully experiment on their own homes and report the results, successful or not, for the sake of knowledge sharing alone.

“The MLS real estate listing service does not yet include third-party verifications for any green building programs, so it’s hard to tell exactly how much more the same home would sell for – or how quickly,” said Rich. Rich cited a Portland study claiming an 18% premium, although he personally thinks that 10% is a more reasonable assumption to make. “People want a green home, but they don’t want to pay more for it,” he added. Sometimes green homes sell more quickly, which can be a big advantage to those looking to recoup their investment.

The value of the LEED brand was discussed. A GreenPoint Rated home can have a score anywhere from around 50 to 300 points – but GreenPoint Rating is only within the State of California. LEED has better nationwide brand recognition, and its three designations – Silver, Gold, and Platinum – are simpler to understand, even if the process to achieve them isn’t.

I’d also hazard a guess that homeowners who’ve actually been through the process or who have chosen to invest in the purchase of a LEED certified or GreenPoint Rated home are likely to be happier and more satisfied with their homes than people who are just looking for something affordable. “Most people hate their homes,” was the astonishing opinion of one HVAC engineer whom I met at a Title 24 class last fall. “If they spend any money on improvements, they want it to be something they can see, like a granite countertop.” Both LEED and GreenPoints are intended to create a home that is more comfortable to live in – less drafty, less noisy, and with better indoor air quality – and I’d guess that many people assume that a high level of comfort and control is out of reach, so they just learn to live with whatever they’ve already got.

Don’t Forget: Factor In Energy Savings

Lower operating costs should be factored in to the value equation as well, particularly energy savings. Both LEED and GreenPoints mandate energy-efficient homes – and they both give points beyond the minimum of 15% over “standard” (Title 24 in the case of California). The exact amount of savings will vary by project, and of course if you invest in renewable energy as well as energy retrofitting, the savings will increase. Don’t forget to factor in sudden utility price increases, not that those ever happen… right, Gray Davis?

It could be argued that one can build energy-efficient homes without getting them LEED certified or GreenPoint Rated. However, having a committed process to enforce a level of structure and rigor throughout the project can help guide decision-making and keep the team focused on the right goals. This is one point Ann Edminster makes in her book “Energy Free” – think about why you’re doing it and what your general strategy will be upfront, and then use it as a road map later on.

The other argument – namely that LEED certified buildings aren’t really more energy-efficient – seems to be based on outmoded assumptions. After reviewing the LEED for Homes criteria that include, among other things, requirements for demonstrated overall energy-efficiency (using the HERS index or, in California, beating the Title 24 energy code by 15%), and Energy Star rating, I don’t think it’s possible to go through all that and NOT have a more efficient building. There’s a whole other set of arguments on the counter-effect of efficient buildings actually encouraging more usage – but that topic will have to wait for another day.

Isn’t LEED for Homes Too Cumbersome?

The main critique of LEED for Homes, especially compared to GreenPoint Rating, is that LEED is cumbersome and inflexible. Why would anyone bother when they could just get the project GreenPoint Rated instead? That’s the California voluntary green building standard from BuildItGreen and it’s being adopted by many jurisdictions as a local requirement anyway.

I put this question out to one of our Green Compliance Plus affiliates, Rob Lehman. Rob said “I’d take GreenPoint Rated over LEED for Homes any day” and mentioned the following items:

• GreenPoint Rating is more practical, user-friendly, and affordable. There are a few mandatory measures and the rest are items you pick a la carte. So it can be less stringent but that’s up to you, how many measures you want to include in the project. Because the barrier to entry is lower, it’s actually more of an incentive to get owners to agree to go through the process. Most California jurisdictions that require GreenPoint Rating have reasonable score requirements, at least for now.

• GreenPoint certification is faster and everything goes through the GreenPoint Rater. The LEED application has to go through review in the D.C. headquarters of US Green Building Council and that alone can take up to a year. The USGBC doesn’t respond to questions that quickly, either.

• LEED is very strict and the process is bureaucratic and inflexible. You have to first get your “scenario” approved (by the D.C. central office) and then if you change anything later on, you have to get those changes formally approved as well. Rich Williams added another piece here. “LEED updates can be hard to figure out. Some of them apply retroactively to past projects, some only to projects done in certain years. But what do you expect from an organization that’s based in Washington, D.C.?”

• The LEED mandatory measures are costly. One example that Rob Lehman cited: LEED requires Energy Star certification, which has an extremely stringent quality of insulation inspection – a lot stricter even than the HERS QII credit. It involves a lot of extra sheet rock, building of chases, and even more site visits than a HERS QII inspection.

Rich Williams actually disagreed about LEED being too cumbersome. “Achieving a basic level of LEED is not that difficult,” he said. “It’s like riding a bike – really hard the first time, but then it quickly becomes second nature.” He sees the main challenge as one of training the production builders to be aware of the standard and to follow it. Still, he says it doesn’t make sense for all projects.

One Sustainable Architect’s Viewpoint

One of the other respondents who had an unusual and dissenting viewpoint was Dan Johnson of Arkin Tilt Architects in Berkeley. They’re just finishing a LEED Platinum house in Palo Alto. Although most of their projects are not certified in any rating system, they are nonetheless quite advanced: off grid, energy independent, passive solar design, renewable energy systems, water collection, extensive attention to sustainable material selection, minimal site impact.

“We prefer to build green without doing paperwork required by a rating system.  Since our future work is based on high performing buildings and client referrals, we already have an incentive to stay at the front of green design without cheating just to make claims. To reduce our clients’ costs, I’d prefer not to spend their money on administrative overhead.  Our name is our green brand.

“I would agree that LEED-H costs the owner lots of money in administrative time, proportionally more for smaller houses. The hours spent on paperwork and calculations do not add any real physical value to the home. The owner could instead spend these thousands of dollars on energy upgrades to the home to get better ecological value for the dollar.

Dan echoed a sentiment that we’ve heard from a few other people, namely, that voluntary certifications don’t do that much to save the planet because the bulk of construction projects will build to code but not beyond. In order to make a real impact of any magnitude, it’s the building codes that have to catch up, and the role of innovation is to prove the concepts, but that’s all it can really do.

“GPR and LEED can validate the work of innovators and help them market their products, but this hasn’t improved the quality of the bulk of new construction [which is mandated by code]. In the absence of high government standards for construction, the LEED award is useful from a consumer’s perspective because it verifies quality claims. However, since LEED-H is no longer very far ahead of the code [in California at least], even the marketing value is not there anymore.

“Now that we have CALGreen, the code minimum has caught up to LEED. It seems that fully of half of the credits in LEED-H are code-minimums now that CALGreen is in effect. So the argument against the usefulness of LEED-H certification has more weight this year. Do owners want to spend money on LEED-H documentation showing that their house meets building code? The cities already provide this service through the plan check and inspection process.

“I would like to see more green compliance handled through the normal code compliance pathway administered by the government, to reduce layers of oversight. It would make sense for LEED-H and GPR to go away, now that the code has caught up, or to raise their standards, to remain relevant as a high bar for innovators. In this regard, PassivHaus and the Living Building Challenge have taken the lead as the high bar for innovators to distinguish themselves. LEED has been so successful in California that LEED is now partially redundant with the building code.

“When a city requires GPR or LEED-H certification as the worst allowable construction, can the architect really take credit for “Leadership…” anymore? In lieu of these award systems, I would like to see HERS launched as a statewide mandatory energy labeling system; new homes are scored on the HERS index during plan check and existing homes are scored at time of sale.

Well, that blew my hair back a little. Both USGBC and BuildItGreen because have been extremely successful because they set a high bar. In California, that bar gets raised up every three years, and very likely these voluntary green standards will continue to improve as well. Sustainability is a moving target, one that every person on Earth will have to wrestle with at some point – on a global, national, local, and personal level – whether we want to or not.

Do’s and Don’ts for LEED for Homes

OK, I’ve recovered sufficiently from the boldness of Dan’s words to abstract a few guidelines for residential architects who may be considering whether to get a California home project “green” certified, either through LEED or through GreenPoint Rating. These notes would still be relevant for other certification programs as well.

• DO review local jurisdictional requirements before doing anything else. Some places require GreenPoint rating based on the sized of the house; others may adopt CALGreen tiers beyond the minimum. Or, they may offer expedited plan checking for certain programs.

• DO ensure that the owner is fully committed to the ideals of sustainability, and not just the label. Why are they doing it?

• DO plan for the chosen certification early, including an ongoing assessment of the impact that the certification may have on project budget and scope of work.

• DON’T forget to factor in any incentive programs that may be available.

• DON’T forget to list the intangible, non-monetary benefits of any sustainable measures. A correctly designed, high-efficiency heating system might cost more, but you’ll be more comfortable. Maybe a lot more comfortable. Ditto using low-VOC materials.

• DO Spend a few hours with a good green building consultant. Spend some time reviewing the required and optional measures in both sets of standards, and make sure that the mandatory measures are feasible and affordable for your project before committing to the whole process. At this point, the owners may feel that they have to choose between scope of work and certification – “If I get LEED certification I won’t be able to afford to do as much as I’d wanted” – so consider carefully how your clients’ money will be spent.

• DO read the manual. Both GreenPoints and LEED for Homes have handbooks describing their requirements in detail. The entire project team should know what the requirements are, and how they will be verified.

• DO try to build up some in-house knowledge of various green building codes and standards: CALGreen, GreenPoints, and LEED. If your’e inclined more towards LEED, get a LEED AP designer on staff if you can. Same goes for BuildItGreen – try to have someone who’s a Certified Green Building Professional, and who knows the GPR system well.

• DO partner with a good green builder – someone who’s worked on LEED or GreenPoint Rated homes before, and who can handle the paperwork.

• DON’T do it just for the label. Jonathan Feldman was emphatic on this point. “Don’t do things just for the points. Do things that you were going to do anyway. You’ll have a better product in the end, better quality control and better durability.”

• DO embrace an integrated design approach. Mitchel Slade, President of Eco-Struction, had some good advice for the entire team, including owner, architect, and builder: “Be malleable. LEED for Homes certification should be one continuous process, not a set of individualized tasks.”

This home in Atherton, CA, built by Eco-Struction, earned LEED Platinum certification.

Epilogue

There’s a lot of room for differing opinion, and no doubt some readers will find some statements above to be objectionable. There simply isn’t room to do full justice to every fact and argument in one blog posting. We encourage you to comment on this article and share your own experiences. All comments are moderated, so please use a valid email address, keep your comments directly relevant to the article, and please be sure that your message is respectfully worded. ;-0