How Much Energy Does an Unsealed Crawlspace Actually Waste?
The U.S. Department of Energy reports that unsealed crawlspaces contribute to 10-30% of a home's total heating and cooling costs. That range depends on your crawlspace condition, insulation type, climate zone, and heating system. For the average Midwest home, the annual cost of crawlspace energy loss can reach hundreds — or even thousands — of dollars per year.
This calculator models those energy losses using your specific home details. It factors in your square footage, crawlspace condition, insulation type, local energy rates, and heating system to estimate your annual waste. It then compares your current situation against the performance baseline of a fully sealed and insulated crawlspace — the condition that building science research consistently identifies as optimal.
The results are estimates, not a professional energy audit. But they give you a data-informed starting point for understanding what your crawlspace is costing you. For the science behind these calculations — including the stack effect, moisture dynamics, and how crawlspace air enters your living space — see our crawlspace science overview. For a full breakdown of encapsulation and repair costs, visit our cost guide.