BUILDING ENVELOPE

This RMI guide explains how to improve a home's building envelope to reduce energy costs by up to 50%. It details the mechanisms of heat loss and gain and provides specific recommendations for insulation materials, air sealing techniques, and window upgrades to enhance thermal efficiency and indoor comfort.

• Investment in building envelope improvements, including sealing air leaks, adding insulation, and upgrading windows, can reduce heating and cooling expenses by up to 50 percent. A typical family may spend as much as $680 per year on these costs.
• Heat gain in homes can be significantly impacted by roof color and ventilation; a dark roof on a sunny day can absorb 70–90 percent of solar energy, which may increase the air conditioner's cooling load by 40 percent if attic insulation or ventilation is inadequate.
• Insulation costs generally range from $0.40 to $2.00 per square foot. The payback period for these investments is approximately five years for those using gas, oil, or air conditioning, and shorter for those using baseboard heating or electric furnaces.
• Air leakage is estimated by the U.S. Department of Energy to add 10 percent to annual energy bills, which is roughly $70 per year for an average home. The most significant sources of air infiltration are floors, walls, and ceilings (31%), followed by fireplaces (14%), ducts (15%), and plumbing penetrations (13%).
• Windows and doors can account for up to 30 percent of a home's heat loss and gain. In the United States, nearly half of all windows are uncoated single pane, while uncoated double pane windows are considered the minimum requirement for hot climates.
• Replacing entire window units is expensive, costing $465 per window or between $5,000 and $20,000 for a typical home, and is generally only recommended for major remodeling or new construction.

APA

Yardi, R., Archambault, T., & Wang, K. (2004). BUILDING ENVELOPE. RMI. https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_HEB1Building.pdf

Chicago

Yardi, Ramola, Tomakin Archambault, and Katherine Wang. BUILDING ENVELOPE. RMI, 2004. https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_HEB1Building.pdf.

Wikipedia

{{cite report |last1=Yardi |first1=Ramola |last2=Archambault |first2=Tomakin |last3=Wang |first3=Katherine |title=BUILDING ENVELOPE |publisher=RMI |date=3 December 2004 |url=https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_HEB1Building.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{yardi2004building, author = {Yardi, Ramola and Archambault, Tomakin and Wang, Katherine}, title = {{BUILDING ENVELOPE}}, institution = {RMI}, year = {2004}, month = dec, url = {https://rmi.org/app/uploads/2017/05/RMI_Document_Repository_Public-Reprts_HEB1Building.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }