Two different households (representing three generations of the same family) moved from two larger single-family homes to this structure on a quiet Belmont street within walking distance of MBTA bus lines, shops, and services. The primary reason for the move was a strong desire to make a substantial reduction in their carbon footprint. The 2-family needed everything: new kitchens, bathrooms, siding, windows, roofing, and HVAC -- so was a perfect candidate for a deep energy retrofit.

DEAP principal Mike Duclos was hired as the consultant to provide energy modeling, HVAC advice, and overall technical assistance. Before the completion of the planning process, National Grid opened up Belmont to its Deep Energy Retrofit Pilot Program and the project became eligible for substantial financial assistance. As a result, DEAP principal Paul Eldrenkamp (also the general contract for the project as owner of Byggmeister) handled the demanding National Grid program application process (

In addition to implementing the National Grid prescriptive goals of R-20 basement walls, R-40 above-grade walls, R-60 roof, and R-5 windows, the project team was able to achieve an air leakage reduction of nearly 90% (from 5700 cfm@50 to 590 cfm@50) and a HERS reduction from 197 to 32. DEAP is currently commissioning and monitoring the project by means of a Telaire CO2 detector, several HOBO data loggers and flow meters from Onset Corporation, and two eMonitors. Data will be posted to the DEAP website as it becomes available, and also presented at the Better Buildings by Design conference in Burlington, VT in February of 2011.

On Dec 31, 2011, this home successfully demonstrated compliance with strict energy use demands of the Thousand Home Challenge program under Option B., and with 17% margin to spare.

On Dec 31, 2012, this home once again completed a year meeting the energy requirements of the Thousand Home Challenge Option B .

A presentation on this home is available here.

Construction and performance specifications are here. has a "Designs That Work" feature story on this project available here.

National Grid has a brief Case Study available here.

A portfolio of our Deep Energy Retrofit work, complete with 'all the numbers' is available here.

Slides depicting the history, scope and project details is available here.

Home Energy Magazine Article on Deep Energy Retrofits (DER) January 2, 2013 - Paul Eldrencamp and Mike Duclos collaborated on the three Deep Energy Retrofits described in the Jan/Feb 2013 Home Energy Magazine article available here. The cover is an image of the Belmont DER