Solar Today March 2013 : Page 23
By R. CARTER SCOTT level — to continue the innovations and help get the word out on affordable zero-energy and energy-positive homes. We seized that opportu-nity. Here’s the story. Asse m bling the D r e am Te am I had been out to the Wisdom Way Solar Village in Greenfield, Mass., after the utility-sponsored Zero Energy Home challenge program resulted in zero-and near-zero-energy homes being built there in 2008. Wis-dom Way had taken third place in the com-petition. (We had taken second place, in an experience I detailed in these pages; see “The Zero Energy Home Challenge,” Novem-(Top) All of the homes started with a super-insu-lated shell. Transformations built 12-inch-thick double-studded above-grade exterior walls. They ﬁlled them with low-density foam for an R-value of 45.6. (Above) The builder added 3.5 inches of high-density foam on the basement foundation walls for an R-value of 20. ber/December 2008 issue). The Greenfield homes were well-built and achieved low HERS Indexes — many around 10. There was an open house for the project, so I made a field trip out for the day. One of the things I noticed in literature about Wisdom Way was a six-figure amount of engineering assistance from the U.S. Department of Energy’s (DOE’s) Building America Program — provided at no cost to the developer. Building America is a public/ private partnership working to accelerate the development and adoption of innovative build-ing processes and technologies for production housing. I contacted Betsy Pettit, president at Building Science Corp. (BSC), and asked her if Trans-formations could get assistance under the same TRANSFOR M ATIONS INC . past — Marc Rosenbaum, Mark Kelly, Mike Duclos, Ben Nickerson and Paul Panish. In addi-tion, Rick Gilles, Bryan Urban from Fraunhofer USA and Luke McKneally from Solar Design Associates came out to help. Joe Lstiburek and John Straube rounded out BSC talent at the charrette, which took place at Joe and Betsy’s barn in Westford. We used the 2008 Farmhouse model, a Transformations design that had been built in Townsend, as a base model and picked it apart. We were looking for ways to increase efficiency, bring down costs and improve the aesthetics of the homes. It took five hours to get through about 25 slides with all of the group’s intense conversations! Ventilation (using a heat-recov-ery ventilator vs. bathroom exhaust fans), keep-ing the basement in the thermal envelope and solartoday.org SOLAR TODAY March 2013 23 Copyright © 2013 by the American Solar Energy Society Inc. All rights reserved. TRANSFOR M ATIONS INC . y Massachusetts-based company, Transformations Inc., had already built several double-studded homes with Home Energy Rating System (HERS) indexes as low as -4 when MassDevel-opment — the state’s finance and development authority — was looking to showcase sustainable housing in 2009. It issued a request for qualifica-tions for developer/builders to design and build moderately priced single-and multifamily homes at its Devens, Mass., residential community. The goal: to provide an example of sustainably built zero-or near-zero-net-energy housing that was practical and replicable in the state. At Transformations, we enjoy being on the creative edge of energy-efficient building, and part of our mission is to share what we learn with others. The MassDevelopment project pre-sented an opportunity to take things to the next M TRANSFOR M ATIONS INC . Building America Program. BSC leads another one of the program’s five teams and has company offices just a short commute from two of our projects. Many of its staff members have con-siderable experience with energy-efficient enclo-sures. I proposed to advance zero-energy homes via the Devens sustainable housing project and two other Transformations developments. Betsy agreed and proceeded to line up talent within her company to work on the project: Kohta Ueno, Daniel Bergey and Honorata Wytrykowska. We started with a charrette including 10 engi-neers and four architects in September 2009. I had invited several building science engineers and architects with whom I had worked in the The removal of the cap on the federal income tax credit for solar electric systems, SRECs markets and falling PV prices are a “perfect storm” for the zero-energy-home world.