Mark English Architects is proud to announce that a recently completed project of ours at 97 Pepper Drive in Los Altos has just received its official “GreenPoint Rated” certification. We spoke with GreenPoint Rater Andrew Arnold of Arnold Engineering, who performed the analysis.

“There are five categories in GreenPoint Rating: Community, Energy, Indoor Air Quality and Health, Resources, and Water Conservation. In order to qualify as a GreenPoint Rated project, a minimum amount of points must be earned in Energy, Indoor Air Quality and Health, Resources, and Water Conservation,” explained Andrew. “There are also two mandatory measures that the project must meet. The first is a 50% minimum construction debris ‘waste diversion’ (recycling or reuse) as measured by weight. The second is a 15% improvement over and above the standard Title 24 energy compliance margin.” A full set of categories and possible items are shown in the GreenPoint Checklist from BuildItGreen.

An example GreenPoint Rated certification from BuildItGreen.

The GreenPoint Checklist for 97 Pepper Drive was filled out and submitted to the Los Altos Planning Department as part of the permitting process. Items claimed for this particular project were then subsequently verified by Andrew during the course of construction.

So how did our house do? Well, it scored 113 GreenPoints out of a possible total of around 300. This maximum isn’t a fixed number, because it’s possible to petition the parent organization, BuildItGreen, to obtain recognition for innovations that aren’t part of the regular list of features in the GreenPoints system.

A section from the GreenPoint Data Collection Form for 97 Pepper Drive.

What was the breakout for those 113 GreenPoints? Andrew sent me the GreenPoint Data Collection Form that he used for 97 Pepper. “Only items that earn points are included,” he said, by way of explaining why our list was shorter than the full checklist. Each individual measure has a point total and a category associated. During the design and construction phases, the GreenPoint Rater has various options for verifying that the selected measures are being implemented correctly, including inspections, photos, material safety data sheets, and invoices.

The GreenPoint Rater also has the option of having a consultant or subcontractor fill out and sign an Accountability Form for selected measures when the Rater needs more information, or when the measure is difficult to verify such as the VOC content in paint. The accountability form, shown below, is signed by the contractor who executed that portion of the construction. It is a means to provide the GreenPoint Rater with a higher level of confidence that the measure was implemented, without having to visually inspect the actual installation. Addtional documentation could include receipts or Material Safety Data Sheets.

So, is a GreenPoints score of 113 good or bad? “The minimum required point total in Los Altos is 50 points, which also corresponds with the minimum point total to qualify as a GreenPoint Rated project” says Andrew. “Originally, the owner only wanted to meet this minimum threshold. However, he ended up installing windows with a better SHGC and U value, a more efficient water heater, and more insulation. These three improvements alone boosted us from 71 GreenPoints to 113 because they helped our Title 24 compliance margin.” If your project beats Title 24 by 15% or more, you can earn more points based on the size of that margin.

One of the measures that earned GreenPoints directly was a quality of insulation inspection or QII. This is one of several HERS field verifications that can boost the Title 24 score – which also adds GreenPoints.

A GreenPoint Rated Accountability Form is used for items requiring third-party affirmation.

Lessons Learned

So how does the rating process itself actually work? Did things go smoothly? “This was my first GreenPoint Rated project,” says Andrew. “Most of the items can be seen during the rough framing stage. I made a list of the selected measures for which we were hoping to score points, and arranged with the contractor when the best time to come and see it would be, based on the construction sequencing and schedule. In this case, the owner was acting as the general contractor/owner/builder, which increased the need for careful communication. All the subcontractors needed to be informed of exactly when items needed to be verified, so that they did not proceed with any subsequent work that could impede the verification process.”

It’s good to be flexible on the GreenPoints during construction, because sometimes measures aren’t executed exactly as planned, and you might have to seek additional points elsewhere to make up for it. “The hardest part for me was helping the owner with data collection. A GreenPoint Rater’s role is to verify that all the measures are being correctly implemented. Normally, all the data is furnished to the Rater; it’s not intended that the Rater would have to perform the legwork. However, due to the learning curve on both sides, I had to perform some tasks that are normally outside the intended scope of a GreenPoint Rater. For example, I had to tabulate the tonnages for waste during construction, and do product research to make sure the materials met GreenPoint Rated requirements. Sometimes the owner would buy first and check later, not fully understanding the exact requirements of the measure. Even though there was a learning curve for all parties involved, overall the project was a success and became the 18th home in Los Altos to be certified as a GreenPoint Rated home.”

“We ran into an issue on the zero-VOC paint because there’s a difference between what BuildItGreen considers to be ‘zero’ VOC and what the paint industry will allow. BuildItGreen requires zero-VOC paint to be less than 5 grams per liter of volatile organic compounds, whereas the painting industry claims zero-VOC for anything up to 10 grams per liter. When the owner knew we wanted to earn GreenPoints for zero-VOC paint, he went right out and bought some, but he didn’t read the fine print. The people at the store told him it was zero-VOC, but we had to settle for a less aggressive designation of low-VOC instead. A low-VOC designation works for anything with under 50 grams of VOC per liter, and we missed some GreenPoints because we went for 10 instead of 5. Even though we were just a little bit over, we had to settle for a low-VOC designation, which doesn’t earn as many GreenPoints.”

You’ve got to do your homework and be very thorough when checking out products. “Most people don’t have that level of attention to detail, but it’s very important in the GreenPoint Rating process,” Arnold cautioned. The GreenPoints system may have finely tiered levels, as with the VOC example. When in doubt, check with BuildItGreen directly rather than relying on over-the-counter information from the retailer.

97 Pepper Sale Information

This Greenpoint Rated property is for sale! For inquiries, please visit http://www.97pepper.com/.

Entry hall of 97 Pepper Drive, a Greenpoint Rated sale property in Los Altos, California.

Andrew Arnold and Passive Houses

Arnold is also passionate about passive houses, or “Passive Houses” as they’re officially termed by the Passive House Institute US in Urbana, IL. (PHIUS has been authorized by the Passivhaus Institut in Darmstadt as the official Certifier of Passive Houses in the US.) The concept and standards for Passive Houses were originally developed in Germany under the term Passivhaus. Arnold is actually helping to create the first certified Passive House in California.

Apparently the hardest part of Passive House certification is passing a very strict blower door test; part of the concept is to create a virtually airtight dwelling with carefully calibrated ventilation to minimize temperature swings. We are hoping to get more information about the new Passive House that Arnold is currently working on, as soon as construction is completed.

When we’re advising our Title 24 clients on their residential projects, the first concern is whether the project will meet the State of California’s requirements for efficient energy consumption – and, if it doesn’t, what measures are needed to bring the project into compliance. A home’s Title 24 compliance “score” is expressed according to the percentage by which the home exceeds the baseline efficiency standards set forth by the California Energy Commission, and these standards are tightened every 3 years.

For the most part, people are relieved just to get their home to zero. For many projects, this is challenging enough. But sometimes, additional measures could boost a home’s compliance score higher, and are much easier to take while construction is already occurring. For example, in a remodel where walls are opened, why not insulate those walls? Well… obviously it’s an additional cost that budget-conscious owners may not want to absorb at the time. But, aren’t they potentially leaving money on the table, too? What value is there in achieving a positive compliance margin?

Since Title 24 is based on a home’s projected energy performance, achieving a higher than required compliance score offers several potential benefits:

1. Lower energy bills
2. Credit in other rating systems like Greenpoints, and
3. Eligibility for incentive programs like the New Solar Homes Partnership.

Calculating energy savings is straightforward matter of comparison before and after. Rebates are also known in advance; for NSHP, the rebate is based on system size and whether the home beats Title 24 by 15% or 35%.

Does Green Matter?

However, establishing a dollar value premium for having a Greenpoint rated home is a little harder. Is there a demonstrable relationship between a home’s real estate property value and its Greenpoint score? Is the Greenpoint rating itself worth anything, even if a home achieves only a modest Greenpoint score?

The question is, does a Greenpoint rated home sell for any more than the same home un-rated?

Well, Seattle green-certified homes achieved a 14% premium, according to a 2009 study by Hamilton Investments which I don’t have but which is referenced in BuildItGreen’s own literature. More on this in a moment.

A good time to establish a home’s actual value is when it is sold. Banks may extend loans based on a home’s supposed equity, but as we know, equity can vanish overnight. A good cash sale, on the other hand, establishes that at least one buyer agreed that the home was worth the price paid.

Don't count your chickens until they've hatched - and don't assume your equity is real until you actually sell your home.

Another important factor for sellers is how long the home sits on the market. A $500K home that sells within a week is a lot better than one that only sells after 9 months; even if it sells for the original asking price, there could be additional financing costs to cover those 9 months if the seller has to put down money on a new home before the old one is sold. That’s assuming they can even get a loan.

Do the Creds Matter?

I began to wonder how much green features actually counted with homebuyers, and whether formal certifications made any difference. Even homeowners who aren’t passionate about environmental issues might be passionate about their equity, especially nowadays. So… does a green certification have an impact on a home’s market value, and what evidence is there to support this?

Despite the Seattle premium referenced above, our Bay Area realtor sources indicate that it’s still not a priority for most homebuyers. “There is a market for the green home, but it is a small percentage.  There would be some added value, but not all that much since you wouldn’t want to limit yourself to only that small pool of buyers,” remarks Rob Rogers of Zephyr Real Estate in San Francisco.

Surveys in Seattle

I asked the BuildItGreen folks, since they invented the Greenpoints system. Amy Dryden of BuildItGreen replied, “There is discussion to have GreenPoint Rated and other green building systems on the MLS. ” (The MLS or Multiple Listing Service is the national clearinghouse for up-to-date real estate listings.)

She continued: “We can reference the Seattle and Atlanta areas, where green building ratings have been integrated onto the MLS there. The results are as follows:

• Homes with a Green rating sold 24%- 50% faster in Seattle and Atlanta
• Sale price for Green rated homes were 4.8%- 24% higher than for non-rated homes (Seattle)
• Resale value was 5-16% greater, compared to a 2% depreciation for non-green (Seattle)”

As of this writing, I don’t have the study that she was referencing. I’ll update this post when I can obtain that information.

So yes, apparently green homes can sell more quickly, for a higher price, and they don’t lose their value as quickly in a downturn. Amy sent me a study by McGraw Hill  which is partly a survey of what people say they would do, and partly a survey of what they are doing, particularly in terms of using green remodeling products. From their summary pages, it says that on average, homebuyers are paying a premium of $19,300 more for a green home, and 70% are more inclined to buy a green home in a down economy.

Furthermore, owners of green homes reported far higher levels of satisfaction with their homes. “Satisfaction” is an intangible quality that is not quantifiable, but then again, it’s a whole lot better than hating your home.

That’s Great for Seattle, But What About Here?

Now, does this translate into a guarantee for Bay Area homeowners that they’ll actually get more for their home eventually if they start greening it now? Umm, I’m not really sure. The McGraw Hill study was a huge survey that covered a lot of topic areas, all based on self-reported responses rather than actual real estate market activity; the sample sizes for the detailed respondents were only in the hundreds, although the initial pool was far larger.

It might be a case where individual measures are easier to quantify than some umbrella “green” designation. In a recent interview with Green Compliance Plus, solar contractor Fernando Valenzuela had talked about solar grid parity and the connection between operating costs and property value as follows: each dollar saved on annual home operating costs adds $20 to the property value. So if you tighten your home enough to save $600 a year, that theoretically should add $12,000 to the value.

Today’s “Beyond Compliance” Will Be Tomorrow’s Baseline

Back to our Title 24 clients. Another piece of reasoning to consider when going “beyond compliance” is simply this. You don’t know what you’ll be doing down the road. Maybe you’ll want to remodel again, and that remodel will have to pass a new and stricter Title 24 code. If the Title 24 has to be applied to the entire home, than all those additional measures, that had seemed superfluous at the time, might turn out to be a good thing in the second go-round.

Maybe you’ll only discover incentive programs after the fact and wish you’d taken their requirements into account sooner.

Or, maybe you’ll be putting that home on the market and discovering at some future time that a Greenpoint rated home is worth a lot more than it was when you did the work. All those efficiency measures you put in earlier could help the rating, as well as generally adding to the home’s market appeal.

Take Destiny Into Your Own Hands and Love Your Home

A lot of green market appeal is based on consumer awareness, and that of course is not entirely predictable. The McGraw Hill study indicates that homeowners are becoming more knowledgeable about green building, which would suggest that it is a priority for some. If owners of green homes continue to report higher levels of satisfaction with their homes than non-green owners, that should also eventually percolate as neighbors and friends trade information in the course of daily life.

A happy home is more than just a dollar investment.

With all the focus on sustainable building, and increased local and national incentive programs, the question is why everyone isn’t on the bandwagon already. Why aren’t homeowners rushing to improve their homes to cut their fuel bills? Well…  for one thing, a lot of people don’t like their homes and don’t feel particularly connected to them, and if they spend any money at all it’ll be for something they can see and enjoy right away, like a granite countertop. Possibly, being better-informed fosters a sense of empowerment in homeowners which in turn contributes to their feeling more satisfied with their homes.

While researching solar technologies, we at Green Compliance Plus heard from solar installers  who all seem to think that architects are hard to work with. So, we spoke with Fernando Valenzuela of Alter Systems in Berkeley about how to design a solar-ready home. Note that only about 5-10% of Alter Systems’ customers are owner/architect teams. Usually it’s the homeowners approaching them directly because they want to “go solar”.

So… why are architects hard to work with? “They have a groupthink… they like design, the look, but they don’t understand systems. They ask questions like ‘why can’t we use this roof’ without realizing that you can’t split up an array. Their projects aren’t always quick, either, and rebates that were designed for may be gone by the time the project gets through approval.”

Valenzuela went on to provide various design tips, as well as insights into new technologies, best-of-breed products, the difference between grid-tied and off-grid systems, costs and returns compared with conventional power, financing options, and the importance of grid parity.

Solar Design Tips for Architects

Consider building shape, roof planes, and orientation: With a remodel, people engage with an architect after the house is already built. It’s really best to take solar into account and design for it from the start. This may include choosing a lot or site that allows for a good solar orientation. Assuming that you do have some power to determine the shape of the building envelope, just make sure you include a nice un-shaded patch of south facing roof around 20 x 30 feet for your PV arrays. It goes without saying to consider proper solar orientation for the building, of course, if you have the option to do so.

Until recently, a single contiguous area was needed for solar arrays, and many products are still configured to work only if all the panels are installed together as a group. The panels should be tilted for maximum solar angle. Some panels lay flat and others can be tilted up; flat panels are aesthetically preferable and better for the neighbors’ attitudes.

Optimize roof tilt: The optimum tilt for the solar panels is your the latitude minus 15 degrees. In California, allow for a south or west facing planar area that is tilted around 20-22 degrees. Utility-scale projects and off-grid systems sometimes use solar tracking devices, but typically residential panels are mounted in a fixed position. The “solar window” is the maximum energy harvesting hours, between 9am and 3pm.

The sun's path across the sky changes according to season.

Assuming that you design includes panels that are built directly into the roof, your roof tilt will determine the panel tilt. “Not too steep, either, ” says Valenzuela. A 30 degree roof tilt is too steep – it’s much harder, and more dangerous, to install the panels. “It works your abs and butt!” laughed Valenzuela. And it’s not exactly “green design” when crews get injured, is it?

The roof tilt also depends on whether you have a grid-tied or an off-grid system, according to Valenzuela.

• Grid tied should be your latitude minus 15 degrees. Grid-tied systems are optimized for summer, because that’s when you’ll get the most energy out of the system, and thus you’ll get more money back at the end of each year.
• Off grid, on the other hand, should ideally be your latitude plus 15 degrees. For off-grid you maximize for winter, because you need the system working even in the worst-case scenarios so that you’re not left in the dark. Basically you want to make sure the system will produce in the winter months.

Allow space for conduits: If solar power is an afterthought, then you may have a visible exterior conduit, which can be less aesthetic than building it into the wall. If you put the conduit under the sheetrock it won’t even show on the outside. But even if you’re not installing solar today, you can accommodate future solar in the design.

Left, a typical retrofit requires routing the conduits wherever you can. Right, allowing a place for solar conduits that's built into the house allows flexibility for future solar.

Be careful with vent placement. “Don’t put vent pipes in the middle of a rooftop solar array. If the pipes stick up too far, they’ll get in the way of the PV panels.”

Make the roofing strong. Roofing should be 2 x 6 or 2 x 10 at 16″ on center for strength. Modern codes want 2 x 4 at 24″ across to conserve materials. If the span is too long, however, this doesn’t account for the weight of the people walking on it to do things like install solar panels. For this purpose, spans over 8 feet need thicker rafters. “We do a lot of retrofits,” says Valenzuela. “Old buildings in Berkeley for example are often 2 x 4 at 24 off center. For these, we may have to put in a brace.”

Keep basic sizing guidelines in mind. The amount of surface area you need for your PV panels depends on how effective the panels themselves are, and how much power the house requires. A rule of thumb might be 500-600 SF of roof (or other area) for the solar array to generate 5 – 7 kW. This covers a lot of places, even desert climates. “Even in the hotter parts of California, with heavy air-conditioning loads, it’s not too far off base,” according to Valenzuela.

Understand the racking systems. It’s good to understand how racking systems operate. “No roof penetrations” are needed. In the future, each panel may come with an independent energy panels with built-in inverters. Innovations include reduced installation time and cost.

Process

Choosing Your Solar Companies: A solar systems company is essentially a contractor/consultant who supplies, specifies, and installs systems. “If your client wants solar power for heating, cooling, electricity, or water heating, then you as the architect will need to establish a good relationship with a company that you can rely on to supply a well-designed system that is appropriate for the programmatic requirements of the home.”

“Try to work with a few solar systems companies that you know well, to get standard products and sizes for components. But don’t rely on just one company, because some companies are over-scheduled right now and orders are going unfulfilled.”

How Long Does It Take? Allow a month turnaround including all permits and paperwork such as rebates.

Customer Experience: So what happens when someone comes to you and says they’re ready to go solar? Here’s what your clients can expect.

1. Site evaluation. The solar consultant will most likely want to visit the house to inspect the roof area, shading, and electrical box. Some houses just aren’t suitable for solar. “Usually it’s a mounting problem,” says Valenzuela. A general rule of thumb for say a 1,200 – 2,000 SF house is to have flat or south facing roof around 20 x 30. Using micro-inverters helps reduce the amount of roof area that you need (read on for more information).
2. Proposal. Assuming the house will support a solar system, the owner gets a price proposal. “I have to ask why they’re doing it to figure out if it’s off-grid, grid-tied, or hybrid system. If they sign off, the paperwork starts.”
3. Permits and Rebates. Local permits for installing a solar system can take as little as a day or up to around 2 weeks depending on locale. The paperwork for tax rebate programs takes 2-3 weeks.
4. Installation. Alter Systems takes 2 days to install, but schedules for 4 days to allow for contingencies such as rain. The owners or occupants can continue to use the home and live in the home while the installation is ongoing.

Grid-Tied and Off-Grid Systems

One basic decision the owners must make is whether to tie their new solar arrays int the power grid. Grid-tied and off-grid systems are totally different animals in some important ways, but as solar power gains mainstream acceptance, it must also be able to integrate smoothly into mainstream infrastructures as well.

• Off-Grid systems are the classic “1.0″ of solar renewable energy. Although they tend to be associated in the U.S. with environmental activism, survivalist movements, and early-adopting technology buffs, they’re also essential in parts of the world where a centralized power infrastructure either doesn’t exist or isn’t reliable.
• Grid-Tied systems are mainly intended to reduce or eliminate energy bills, as in Net Zero homes. It’s a more mainstream market than either the early adopters or the green contingent. A main motivation is likely to be cost savings.

Although grid-tied systems are a newer concept, they are likely to be the wave of the future in industrialized countries. The components of a grid-tied solar system are the panel arrays, a power inverter to convert the direct current generated by the panels into the alternating current used by household appliances, a manual power disconnect, and of course the utility company’s usual infrastructure: the meter and switch box.

A grid-tied system is simple and straightforward. There is no need to store power onsite. Power generated is fed directly back into the grid, and home power needs are drawn also directly from the grid.

An off-grid system has more components, because of the onsite power storage requirement. In an off-grid system, the solar arrays feed into a combiner box which balances the inputs from each array. The combiner box combines or branches together the PV arrays/modules and then takes all the power through one set of leads to the charge controller. The controller makes sure your battery is charged correctly, and prevent over-charging.

The advantage to this type of off-grid configuration is the ease with which you can add supplemental power-generation systems such as microhydro or wind turbines. The goal of an off-grid system is to keep the batteries fully charged at all times. If there’s a grid tie-in, the battery won’t “sell” back to the grid unless it is already fully charged.

Which configuration you choose for your solar system depends on the reason why you’re going solar in the first place. Homeowners typically adopt a grid-tied system to save on energy bills, reduce their carbon footprint, and perhaps to show off to their neighbors. Valenzuela cites an estimate from the Journal of Assessors and Appraisers that for each dollar you can shave off your annual home operating costs, you add $20 to the property value.

According to Valenzuela, based on his experiences with his own customers, homeowners might choose off-grid because they’re in a remote area, and either it’s too expensive to bring the grid out there, or it exists but is not completely unreliable. “Some people do it because they hate public utility companies just on principle,” notes Valenzuela. “They’re also more likely to be DIY types who are comfortable assembling their own systems,” he adds.

An off-grid system includes an onsite storage battery. It's designed to be self-reliant. The homeowner can add a grid-tie option as shown above.

So what are the pros and cons of each type of solar configuration? Grid-tied systems require less equipment and employ simpler configurations; on the downside, they’re limited based on inverter sizes.

With off-grid systems, it’s easier to add supplemental renewable-energy systems on the side for things like wind or microhydro.

It's easier to add supplemental power generation systems to an off-grid system with its own battery storage.

Off-Grid for Villages: A typical residential home might need a 6kW system. For sites such as an army base, a remote ranger station, or a farm with multiple buildings, a system called AC coupling can deliver 20 kW or more. Basically it’s a way to create your own micro-utility company, and collect power from solar arrays on several buildings, using one central inverter (such as the Sunny Island off-grid inverter from SMA Solar Technology) and a central storage area. “This type of installation is very useful in places like the Caribbean, island countries or places without any infrastructure,” says Valenzuela.

Could you implement something like that in a city neighborhood, I wondered? A residential collective of some sort, for people who live in urban areas but still want to have totally independent self-generated power, and who want to pool their money to invest in economies of scale? “You’d have to do all your own wiring,” Valenzuela responded. “They’d have to be fairly close together.”

Well… with the geek factor in this area of the country, I wouldn’t be surprised if it’s already happening. After all, if a few homes drop off the grid on a single city block, how would we ever know?

Solar Grid Parity

I didn’t even know what this was, but with all the talk about the ROI of solar systems vs. fuel cells vs. high-efficiency but conventional systems, it’s a very important concept. Solar grid parity is a tipping point in the energy marketplace when the cost of energy production for solar power will be equal to or less than the cost of generating conventional, fossil fuel-based grid power.

A common comparison is dollars per watt or cost per kWh. U.S. average power prices for last year ranged from 5 – 15 cents per kWh, averaging roughly around 10-11% (businesses were 1 cent cheaper).

This number includes upfront investment in equipment although of course there’s debate over how to calculate it and when this momentous day will actually come. 2012 seems to be a common guess, although coincidentally that’s also the end of the world, according to the Mayan doomsday calendar).

Prediction: “a number of solar companies will hit a long-pursued industry target of $1 per watt by 2012.”  This “race towards $1 per watt” means that “within a few years solar panels will be able to generate electricity cheaper than the grid in many regions of the world.” (Sunnier regions have a bigger solar payoff, not surprisingly.)

Another claim is that we can reach 2012 grid parity in “almost half the US” and he also notes that there are several ways to calculate grid parity.

Even 4 years ago, solar was still pooh-poohed as a boutique technology for wealthy do-gooders or conspicuous consumers. But that was before tax rebates and stimulus dollars made it easier for new owners to “green” their homes. Other factors include improved component efficiency and a wider array of creative financing options such as these options from SunRun to purchase solar power as a service, to lease the equipment to the owner, or to help owners seek solar financing through local municipal programs.

So, is it a sure thing that in 2012 we’ll all be putting PG&E out of business? Doubtful, but there’s definitely a sense that price parity is coming, it’s just a matter of when. For example, higher interest rates could hurt financing, and if grid prices fall, parity won’t be reached nearly as soon. For those who prefer to focus on equipment efficiencies, there’s a rather geeky engineering article from BP Solar that discusses current and future efficiencies, including emerging new technologies such organic photovoltaics and nanocomposite solar cells.

The $1 per watt number is disputed as overly simplistic on one investor blog: “PV’s competiveness with the grid varies wildly based on the region… The idea that module prices need to come down to $1/W for solar to be competitive is misplaced at best” because “PV is already at or near parity with the grid in a number of markets”. This blog also includes a good discussion of calculating the cost of various types of conventional power, including nuclear.

Solar Financing Innovations

For homeowners who want to finance their solar installation, three good sources are:

• Tax rebates
• Municipal funding options through property taxes
• Bank loans

In the second case above, this is a plan being adopted in some localities such as Santa Rosa. Basically, the city obtains the funds for solar installations at a very low interest, say 3%. The city then loans it out to homeowners at a slightly higher but still reasonable rate, say 7%. The owner then pays back the loan in the form of an extra property tax surcharge every year. If the house is sold, the new owner is responsible for continuing those payments as part of the home’s property tax bill, and the new owner of course enjoys the reduced energy bills in the meantime.

“Some owners just pay for it with a credit card,” said Valenzuela. I can’t imagine plunking down $35-$60,000 on my card but then again, I can’t imagine watching the national average of television, either. “Every dollar decrease in operating cost adds an extra $20 in property value,” said Valenzuela, “but equity is fake money. So, we don’t include this increased equity on our cost/benefit analyses that we show customers in our proposals.”

New Solar Products

During the course of our conversation, Valenzuela mentioned some of his favorite new solar technologies. In no particular order, here they are.

Solar forced air heaters. These devices are installed on a south-facing wall or roof and are best used as a complement to other heating systems, a boost but not a replacement. They’re small and relatively efficient, at least compared to PVs. A single 8-foot panel is enough to heat a small room. They use no fuel and have no moving parts except a fan to draw cold air into the panel and push heated air out directly into the room. They don’t work as well on cloudy days, obviously. And you don’t even need fancy PVs or heat collectors: here are some ingenious DIY solar air heaters made from recycled aluminum cans.

This 8-foot solar wall air heater from ClearDome Solar in San Diego can heat up to 500 SF of residential space.

Micro-Inverters. Green Compliance Plus has mentioned the breakthrough of micro-inverters in a previous post – basically, by having separate inverters for every PV panel in a solar array, you can harvest more energy because shaded panels no longer bring down the performance of the entire array. One maker of micro-inverters is Enphase Energy. Valenzuela waxed almost poetic about Enphase products: “At the recent Green Building Expo, their booth was mobbed while the big players were empty!”

FLEXpower ONE Off-Grid Solution. Valenzuela made special mention of one particular product from OutBack Power called the FLEXpower ONE. He recommended this for total off-grid systems including smaller installations such as boats.

Xantrex XW Grid-Tied Solution. The Xantrex XW from Schneider Electric is recommended for homes that are grid-tied with a battery backup. “It’s not quite as flexible as the OutBack for very small installations, but it’s easier for designers, because it’s a high-quality product and you can scale it up,” says Valenzuela.

But what should architects really know? “Use Enphase!” says Valenzuela.

“Sustainable residential design is transforming from a market niche to a widespread set of consumer priorities… because consumers realize that going green is good for their wallets.” So sayeth the AIArchitect, official voice of the American Institute of Architects – and they’ve quoted us, along with a slew of other designers and builders.

It’s official. Homeowners are moving beyond ideology, and realizing that investing in a green home will do more than save the planet – it’ll save their savings! Does anyone remember California’s soaring electric rates from 10 years ago? Don’t we want to be LESS vulnerable to fluctuations in fuel prices?

Yes, there are many philosophies, everything from producing more self-generated power to consuming less. (Wait, consuming less? who knew?) But, design clients themselves are now more savvy about what’s out there, and that’s a good thing. It’s not just about bamboo flooring anymore. And builders are catching on, too.

Many of our Title 24 clients have been asking us whether they can safely specify LED fixtures that would qualify as “high efficacy” lighting under Title 24. Could one conceivably create an entire lighting plan for a custom home using mainly LEDs, and if so, would it pass Title 24? Would it look any different to the untrained eye? Would it actually use less energy? Or, are LEDs better used as a supporting component in a diversified lighting plan rather than as the main workhorse? Are LEDs sustainable to manufacture? Do they use less power in a real-life installation, not just in the lab?

The answer to LEDs in California is a qualified but definite yes. There are definitely products out there that will comply with California’s energy codes, and we should see more coming to market this coming year. The issue is not the LED lamp itself, but the housing, because the fixture’s efficacy depends on the entire assembly.

As a designer, there’s some fine print to watch out for. To say a product “complies” with Title 24’s high-efficacy standards involves certification and documentation. There are many more products that would comply, but they’re made by smaller local manufacturers who can’t always afford the lengthy and expensive certification process. These demi-compliant products can be sold to retail consumers as after-market products, but without certification they wouldn’t pass a formal, by-the-book inspection. Manufacturers of lighting fixtures can test their own products of course, but to get a product certified means paying for an outside lab to test the products, and of course re-certification every time the code changes.

On the plus side, many building inspectors are favorably disposed towards LEDs and are willing to consider the products themselves on a case-by-case basis, as long as the product data is credibly presented. One of the lighting designers we spoke with, Henry Chu of Halogens Inc in Millbrae, CA, makes his own LED fixtures and is currently presenting some of his new products to local building officials for their feedback.

LED chandelier designed by Kenzan Tsutakawa-Chinn

High Efficacy Definitions

Title 24 has various requirements and incentives to encourage the use of high efficacy lighting as measured by the amount of visible light emitted per watt of power consumed. The required threshold varies according to the number of watts in the luminaire, as distinguished from the lamp (bulb) itself. 

Most people associate LEDs with the lamp component only, because they’re used to seeing them used singly as indicator lights on machinery. A luminaire is the entire assembed fixture, including lamp, ballast, housing, and connectors. Only luminaires can be high efficacy. It’s really the luminaire, or the entire fixture, that determines the efficacy – the bulb by itself is not enough.

• Under 15 watts, must have an efficacy of 40 lumens/watt
• Between 15-40 watts, must have an efficacy of 50 lumens/watt
• Over 40 watts, must have an efficacy of 60 lumens/watt

Three LED lighting designs from Litefuzion.com. Designs by Iestyn Davies and Jack Wimperis.

This prototype fixture uses LEDs and fiber optics.

LEDs can be used as color accents in room designs without turning the place into a disco. This image from Litefuzion.com; design by Jack Wimperis.

“LED lighting still has a long way to go,” says Hiram Banks, a San Francisco lighting designer recently profiled on our sister blog, The Architect’s Take. Product unknowns include optimal operating conditions and product life. “Most data we have is hypothetical based on lab studies. There are not many long-term studies because it has not been around long enough. So, when scientists and manufacturers say that white LED lighting has a lifespan of over 40 years, they are saying that with hypothetical data from the lab. There are many factors that determine the life of the LED light source, and they are becoming more evident as LED installations start to age. For example we have just learned that LED lighting needs a lot of air circulation and does not like heat, which can kill it in less than a year!  We do not know if over time the light output starts to diminish as in most other light sources, or if the color starts to change.”

Color accents work in bars, too, although I feel like I'm about to get on a Virgin Atlantic flight. This one also from Litefuzion.com

This customer service center by Future Group Lighting Design integrates color-changing LEDs with conventional lighting. The stripes change color depending on the time of day, with warmer tones in the morning and bluish tones in the evening.

There are three ways to make white light using LEDs:

This fully programmable LED array was created by 3 Way Labs in Menlo Park, CA. I've seen their work in person and I was amazed at the programmatic controls of color, light level, and the patterns as well - surprisingly organic and natural in flow.

Sprinter S Light shower enclosure by Sprinz, a German company

This LED installation was designed by Leo Villareal at the National Gallery of Arts. Photo: Min Batsone

Links for Further Study

• Interesting page from Light Emitting Diodes.org, all sorts of wavelength data for LED white light sources.
• Excerpts from a Californa Energy Commission PDF slide show: Title 24 2008 Changes to Residential Lighting Standards
• 3 Way Labs, maker of the “Cubatron” series of programmable displays
• Litefuzion, a UK-based company doing interesting LED lighting designed fixtures
• Case study from Future Group Lighting Design, also in the UK

The Passive House Institute in Germany  has improved upon American ideas from the 1970s and re-branded it as PASSIVHAUS. Superinsulated homes have been built in many locations in the U.S. over the last 30 years, as Dan Hagen P.E. describes in his letter on the ASHRAE web site.

Passive houses use significantly less energy than do existing or new conventional residences. In fact, they use so little heating energy that a conventional heating and cooling system is mostly unnecessary. The house stays warm by recycling heat that is already being generated by internal sources – lighting fixtures, stoves, toasters, dryers.

This prefab home from WeberHaus is a contemporary example of a passive house.

Now, the Passive House Institute has developed an energy modeling program called the Passive House Planning Package (PHPP), created by Dr. Wolfgang Feist. This program calculates energy savings to anticipate the monetary payback from a superinsulated home.

Here at Green Compliance Plus we purchased PHPP to see what it was all about. It’s similar in some ways to the Title 24 modeling packages, in that it determines whether the finished residence will meet the Passivhaus energy consumption goals. However, it goes beyond Title 24 in both its reporting and intent.

Title 24 compares a project to a “standard model building” of the same size and orientation, and tells you whether the proposed design is more or less efficient than the standard model. The Passivhaus calculations require more input data than Title 24, and provides reports of the actual energy usage in kWh or therms. It also considers CO2 reductions, which is the home’s carbon footprint.

Examples of passive houses in Austria and Ireland. On the left, the Austrian multi-family project “Satzhof 2″, by Nabih Tahan, was completed in 2000, to the Low Energy standard, which was the generation before Passive House Standard.

Interview with Architect and Passive House Expert Nabih Tahan

To learn more, our own Alan Hugenot interviewed SF Bay Area Architect Nabih Tahan,  who recently completed construction of a Passivhaus residence in Berkeley and is a well-known speaker on the topic of passive houses.

Bay Area architect Nabih Tahan, an expert in passive houses

What kind of building is adequate in our mild Bay Area climate (Title 24 climate zones 2 and 3) to meet the PHPP standard?

As with conventional Title 24-based designs, many different building envelopes can qualify, and the PHPP model is used by entering different values for the insulation, fenestration, thermal mass, etc. until the optimum design is achieved. Generally, the Passivhaus envelope is more airtight than are conventionally designed residences. In a Passivhaus, the ventilation is controlled by the continuous mechanical ventilation system, which also handles all internal heat collection and redistribution. The underlying principle is “Build tight, ventilate right.”

If a Passivhaus does not require a conventional heating system, then where does the heat for the residence come from?

Tahan: In a typical house, every light bulb, computer, refrigerator, oven, hair dryer, and toaster generates heat. [In a passive house,] This heat cannot escape because the building envelope is tightly sealed. The only place this heat can go is through the ducts of the constant ventilation system which utilizes a heat recovery ventilator to transfer this heat from the air being exhausted into the fresh outside air being supplied into the house. This provides both energy efficiency and excellent indoor air quality. Typically, a passive house reduces the heating or cooling loads by 80 to 90%. So, a backup heating system is still necessary to provide the remaining 10-20% that is required.

What efficiency levels do passive houses achieve?

There are three measurements that define a passive house:

• The building envelope is constructed so that the heating requirements will not exceed 1.4 KWh / square feet per year.
• The outside source energy requirements will not exceed 11.1 kWh / square feet per year.
• The building shell is so airtight that it will pass less than 0.6 air changes per hour at a pressure above an ambient level of 50 pascals.

More Links to Nabih Tahan’s Material

Interview Q&A on Metro Green Business

Summary of a talk he gave at BuildItGreen this past February

There’s more than one way to be green, and the San Francisco Chronicle has featured Mark English touting old-fashioned thrift over more showy forms of environmental non-consumption – even the very same stuff we were talking about only last week.

So yes, reuse where you can, and make your home more efficient first, before you put in those solar arrays that will make your neighbors “green” with envy. Then when your neighbor is showing off his new solar roof tiles, you can counter by saying that your home uses so little energy already that you decided to put your money towards a “living carpet” instead.

Does it pay to be nimble, light, and alone these days? As the reeling economy continues to wreak havoc on the design and construction industry (2,000 fewer people were working at architecture firms in the month of April alone) architects are being bounced from their jobs at traditional design firms and wondering where their skills fit into the economy’s seemingly willful refusal to build buildings. Experience from other sole practitioners and small firms that offer services to architects and architectural clients suggests that the best business model today allows architects to use their diverse skills wherever they see fit—plugging their expertise into hyper-specific micro markets that are too small for a large firm to work in, yet large enough to keep paying the bills. Four Bay Area architects have been doing just that, often after long and familiar experiences with large, traditional design firms. Though their practices are vastly different, they’ve all found that the freedom and flexibility of their consulting practices have allowed them to bob, duck, weave, and advance in a worsening design market.

AIArchitect This Week | Consulting Practice Niches Create Shelter for Architects in a Thorny Economy

Here at Green Compliance Plus (GCP) we also offer NON-RESIDENTIAL TITLE 24 Compliance Services, as well as Residential and Non-Residential Building Systems Commissioning Services for new construction, and re-commissioning for existing buildings.Architects and developers who have historically concentrated in the Residential markets, are now beginning to take on Non-Residential projects to keep their order books full during this the economic downturn, and when they do, one of the questions which comes to mind is,

“Where do we go with our Non-Residential projects to find the level of service we have enjoyed at GCP with our Residential designs?”

The short answer is “Simply stay put”.  At Green Compliance Plus our staff includes T-24 documentation authors who are recognized by the State of California (CABEC) as Certified Energy Plans Examiners (CEPE’s) for Non-Residential projects, which includes everything from high rise offices to hospitals, bio-tech facilities and electronics wafer fabs, restaurants and cafeterias, or even chemical plants. And over the last 20 years Alan, our Director of Energy Compliance, has served as the lead Commissioning Authority (CxA) during the start-up phase of numerous apartment complexes, office and laboratory buildings, industrial facilities, medical, pharmaceutical and electronics facilities projects, overseeing all the functional performance testing and performance verifications.

In Non-Residential modeling, Alan has 20 years experience with DOE 2.2, the U.S. Department of Energy’s program first developed by Lawrence Berkeley Laboratory in 1982, and it is DOE 2.2 which forms the basis for the models behind the more widely known T-24 programs, Micropas and EnergyPro. But, those two popular programs are mostly limited to Title 24 applications.

Today, with the advent of LEED and GreenPoint rating requirements for buildings, as well as the other incentive programs which are coming into the picture, there are now many energy measures (EM’s), which your client may be considering, but which are not yet recognized by Title 24. But, these additional measures need to be modeled and analyzed, and unless the model is based on E-quest/DOE 2.2, this will be difficult to do. So, this is where E-Quest / DOE 2.2 makes a better energy model. This versatile program allows modeling of any EM you can think of. Also, by utilizing the energy rate data available from the utility companies, E-Quest/DOE 2.2 can generate Life Cycle Cost (LCC) data, which allows you to figure the pay-back for each EM. This is also the program used by most mechanical and electrical engineers in their building systems design. And, beginning in 2004, it has been fully approved by the CEC for Title 24 compliance documentation and has been continually upgraded and re-approved for T-24 (2001), T24 (2005) and will also shortly be approved for T-24 (2008).

“At Green Compliance Plus we take the worry out of Title 24 Compliance”.

We also provide the Non-Residential HERS-Rater duct testing and verifications, which will be required for Non-Residential Construction after August 1.