DEEP ENERGY RETROFIT - somerville, ma
When our clients purchased a tired 1920's house in a desirable, walkable neighborhood, their mission was to renovate and stay a while. As the structure needed major work, they seized the opportunity to go well beyond the minimum energy efficiency measures required by code and do what is called a "deep energy retrofit."
By Taking a whole-building approach and addressing many systems at once, much greater energy efficiency could be achieved.
Conventional practice is to install insulation between exterior wall studs and roof rafters. This leaves paths for heat loss through the structural members and small gaps around the framing members. In this deep energy retrofit, a continuous 4" thick jacket of high performance insulation was applied over the entire house, like a cozy on a tea pot.
The existing eave trim and rafter tails were removed so the new insulation jacket could be continuous at the wall-to-roof transition. This eliminated a notorious insulation weak point and source of winter ice dams.
Once the structure was super-insulated, a down-sized, very high efficiency HVAC system could be installed. Preparations were made for future solar domestic hot water panels and photo-voltaic panels on the roof. The result of the typical deep energy retrofit process is a home that is over three times as energy efficient as before.