This guide was produced by Building Science Corporation (BSC) for the MassSave Energy Efficiency Program Administrators: the Berkshire Gas Company, Columbia Gas of Massachusetts, National Grid, New England Gas Company, NSTAR, Unitil, and Western Massachusetts Electric Company.

BSC would like to acknowledge the support and guidance of the sponsoring utility Program Administrators particularly Marie MacMahon-Meehan of National Grid who spearheaded the project.

We must also give special recognition to the builders, consultants, designers and homeowners who participated in the Deep Energy Retrofit (DER) Pilot programs administered by Massachusetts's gas and electric utilities. And to David C. Legg, Ms. MacMahon-Meehan's predecessor at National Grid, who championed the cause of DER within utility efficiency programs and was responsible for launching National Grid's DER Pilot. The efforts of these pioneers paved the way for broader adoption of DER methods. Indeed, the experience provided by these pilot projects proved essential to recognizing challenges and identifying solutions that would be widely applicable to high performance retrofit of wood-framed homes in New England.

Finally, we would like to acknowledge the foundation for the present work established in the work of Dr. Joseph Lstiburek and Ms. Betsy Pettit, FAIA, founding partners of BSC as well as Armin Rudd, Christopher Schumacher and Dr. John Straube. If portions of this guide bear resemblance to articles or presentations by Dr. Joe, Betsy, Armin, Chris or Professor Straube, it is not merely coincidence. Rather it is a consequence of the profound influence that their work has had on our understanding of buildings.