We are excited to contribute to this ambitious project by the City of Bridges Land Trust. This partner has planned to install both a heat pump water heater and a ductless heat pump for the finished attic.
E3 proposed adding interior wall insulation to this double-brick home. Framed walls also facilitate new whole-house electrical rewiring, while 2 inches of Polyiso foam board sealed around the perimeter add R-13 to the wall.
Detailed plans were also developed to improve the attic knee walls, including adding rigid foam behind the knee wall insulation, sealing the floor joist gap below the knee wall, and adding vents to these sections of the finished attic.
Additionally, this home will receive a triple-pane windows with a U-value of 0.2, SHGC of 0.24, providing approximately 50% better performance than a typical window.
The work is now finished, and the final blower door measurement showed 2815 CFM@50, or 10 ACH@50 for air leakage. This 2062 s.f. home now features all updated systems and, because of the use of heat pumps, cut the energy use by 32%. Notably, only after E3’s wall-insulation upgrade did the utility costs show a meaningful drop—saving $490 annually and bringing the total energy reduction to 48.5%. Other measurable results include an improvement in the Home Energy Score from 1 to 5, and a decrease in annual CO₂ emissions from 12.5 tons to 7 tons. I think we should be collectively proud!
