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.
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.
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.
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 was for sale but has since been sold!
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.
About the author
Rebecca Firestone has been working in the Bay Area since 1998 as a technical writer, business content developer, architectural filing lady, marketing director, and sorcerer’s apprentice.