Performance of Side-by-side South Texas Homes

As the use of spray polyurethane foam (SPF) insulation is increasing in both new and existing homes, prospective users often ask the question: “How much can SPF impact my heating and cooling costs?” To provide the most accurate answer to this question, one would need to construct two identical homes with the same location and orientation: one with and one without SPF insulation. The homes would need to remain vacant and monitored for energy use for at least one year. A recent study came very close to using this type of approach.