Building Envelope Integral to 1.0’s Energy Efficiency

Going green can be affordable, buildable, and certified—especially when implementing a solid building envelope.

By Amber Materna

Birthed out of an idea to be Affordable, Buildable, and Certified, the ABC Green Home collaborative effort came to fruition in October, ushering out elected officials, media, and key opinion leaders of California’s home building industry to the Orange County Great Park, in Irvine, Calif. The dedication of green design found within every component of this home proved to add up to something very special, thanks to the genuine effort from every party involved.

Headed by both Southern California Edison’s (SCE) John Morton, program manager of California Advanced Homes, and Green Home Builder magazine’s Publisher Nick Slevin, the green home, a single-level craftsman style boasting three bedrooms and two baths, came equipped with nearly everything to prove its eco-efficiency. While both parties and their partners learned much throughout the process of building this home, it was really the security of the building envelope that stood out as the obvious winner of green gusto.

While careful attention was given to every aspect of the home, the ABC Green Home Project is literally airtight where it matters most, the building envelope. Ana Lall, commercial business development, Demilec USA, Inc., explains it most succinctly: “All structures, including a home, have air gaps and crevices that allow air to infiltrate the building,” she said. “Weather, pressures, and conditions beyond your control, exploit these openings allowing air to infiltrate a home.” This is where the problem lies, and why project managers of the ABC Green Home chose to utilize closed-cell spray foam in conjunction with solid lumber construction. According to the Department of Energy, “up to 40 percent of energy loss is due to air infiltration. When air from the outside replaces the air in a home, it is called a ‘Natural Air Change.’ Homes built years ago can have more than three Natural Air Changes an hour,” Lall said.

It’s easy to understand why this might be problematic for energy-efficiency. According to Lall, “[Three Natural Air Changes in one hour] means that conditioned air inside a home could leak out and be replaced by outside air up to 70 times a day, requiring occupants to heat or cool outside air that continues to infiltrate into a home.” However, Demilec’s closed-cell spray foam, named because all of the tiny foam cells are closed and packed together—protects against “Natural Air Changes” while also providing insulation. Once sprayed, the foam expands up to 120 times, filling “every crack, gap, void, or crevice as it creates an air barrier,” which in turn acts as exemplary energy-efficient insulation, energy efficiency, and controlled air quality. The perfect pair to this insulation is an obvious choice, in that it’s already the standard builders have gone by: lumber. “Lumber is truly one of the few renewable and sustainable building materials in use today,” noted Pete Meichtry, Ganahl Lumber, continuing that “Lumber production today is the most environmentally friendly when compared to other similarly purposed products.” Both ideas seem fairly simple and relatively obvious, but as Manny Gonzalez AIA, LEED AP and principal, KTGY Group, Inc., best put it, “the best features are the simple low-tech ones.”

This might be why Gonzalez and the aforementioned John Morton credit the walls as to being their favorite features of the house. “Just by using 2×6’s and 24-inch centers, we dramatically increased the insulation value of the exterior walls without using any additional lumber product. Features like this are where homebuilding should be heading,” Gonzalez shared, with Morton adding that “Once you put up the drywall it is very rare that anything behind them is changed…any mistakes made behind the walls are there for the life of the home, making it harder to overcome those misstep with other systems in the house.” Unfortunately, this best, and most effective, aspect of the ABC Green Home is also one of the most easily adulterated aspects. “The biggest challenge was the need to ensure each trade representative was properly trained and fully understood the goals of the project,” Morton explained. Education of why the building envelope must uphold its integrity was important to not only communicate to the trades installing the insulation, but any and all of the professionals working within the walls. “There was a lot of coordination required on this project and the challenge was to make it work,” Morton continued.

However, the outlook for the trades’ willingness to learn, and teach others, proved to be an optimistic light for the project, at least when viewed through the lens of the ROP program. “The biggest surprise to me was the way the trades fully embraced the high school training program we had. I was apprehensive at first how the kids would be received on the job site. To the trades credit, they fully embraced the program and gave the kids a once in a lifetime experience that I am sure they will never forget,” concluded Morton.

Undoubtedly, there have been many lessons learned throughout the ABC Green Home project by contributors that won’t so quickly be forgotten. Nicole Feenstra, project manager of the ABC Green Home and producer of the Webseries, learned more than she expected from the experience as a whole, specifically in what really goes into it. “It was like birthing a baby,” she said, half-jokingly. “I think seeing what worked and what was a set back, you feel for everyone that’s on the process. When you talk to builders, or manufacturers you have a real understanding of what they’re going through,” she continued, emphasizing that what it really came down to was simply knowing the process. “What are the things you can do to go green at the very basic level? That’s why the building envelope and spray foam is integral to the project.”

If the building envelope and insulation ranked as one of the highest points of interest for the partners inside the green home, the mere endeavor of it all ranked highest overall. Michael Knight, designer, Urban Arena LLC, took interest in what this project could mean for sustainable landscape design, especially under a Net-Zero home. “Rainwater is the main natural resource that landscape design has to work with and is, therefore, a primary consideration when designing a Net-Zero landscape. Having a cistern allows us to capture stormwater and reuse it for landscape irrigation,” he shared, adding that “this type of system is rare and its implementation at such a visible project provides a great opportunity for the industry and the public to observe and learn about its benefits and feasibility.” The public’s introduction to such design is the first step for helping communities realize the benefit of sustainable design, and also arming Urban Arena with “a tangible example to point to when discussing affordable, buildable, and sustainable design options,” said Knight.

Southern California Edison, too, used the home as not only a testing board, but also a continuing measurement of energy resources. “Edison will take all the data to figure out the true performance of the features included in the house. These results can help shape the direction of how we help the builders to improve their energy-efficiency,” explained Morton. ”The data will also help validate or improve our predictive modeling methods so that we can better anticipate the true performance a home can have while still in the planning stage,” he continued. Edison was also given the opportunity to test out the Demand Response system; a tool homeowners can use to partner with SCE in attempts to drive down their energy bill. “Through the smart meter on the house and the AMX system in the house we work together with the home to put the house into energy saver mode. This helps Edison on those high power consumption days as well as reducing the home owner’s energy bills,” explained Morton, reassuring that “as always, though, the homeowner has the total control. If the save power signal is sent to the home at a time the homeowner needs to use the house there is always the choice to override the signal; nothing changes in the home.”

 

The project has proven to be educational to both the partners and the public, and will continue down this path long after the home has been donated to the Habitat for Humanity thanks to these strong partnerships, which according to Beth Krom, chair, Orange County Great Park Corporation, is exactly what she expected. “The ABC Green Home fit perfectly into our mission. We like to think of ourselves as ‘more than a park.’ Beyond our commitment to environmental stewardship and education, we believe in partnership,” she shared. And partnership in support of environmental stewardship and education is exactly what arose.

So while the ABC Green Home 1.0 comes to an end, the home is open to the public for self-guided tours Mondays, Wednesdays, Fridays, Saturdays and Sundays from 9 a.m. to 4:40 p.m. Current participants look ahead to ABC Green Home 2.0, anxious to learn even more, and as Gonzalez from KTGY said to get a second opportunity “is a chance to underscore the success of the first home, while showing that any scale of home can be affordable, buildable and certifiable.”