Significant energy savings will result from compliance to the foundation insulation recommendations in ASHRAE Standard 90.2P, "Energy Efficient Design of New, Low-Rise Residential Buildings" (ASHRAE 1987). This paper summarizes an assessment of current U.S. energy savings from foundation insulation and estimates future savings resulting from broad-scale adoption of ASHRAE 90.2P. The assessment is based on the premise that the detailed analysis behind ASHRAE 90.2P and its systematic method of determining insulation levels in a balanced manner will allow it to become the accepted base energy performance standard for all residential construction.

The total energy currently being saved by foundation insulation (30% of 1.7 million new units) in one year’s worth of new housing starts in the United States is estimated at 9.6 × 10¹² Btu/yr (10.1 PJ/yr [petajoule = 10¹⁵ joule]). The full compliance with ASHRAE 90.2P leads to more than a doubling of current foundation insulation energy savings. The extrapolation of existing practice and the addition of other contributions resulting from compliance with ASHRAE 90.2 lead to an estimated energy savings by the year 2010 between 0.38 and 0.45 quad/yr (400 and 475 PJ/yr [quad = l0¹⁵ Btu]).

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