Insulation Savings Calculator

Estimate potential annual savings from insulation or air-sealing improvements using your current heating and cooling energy use. The tool is designed for scenario testing: start with a measured or bill-based heating and cooling baseline, then vary the assumed percentage reduction to see what level of annual savings would be required to justify a proposed project cost.

WCL / INTERACTIVE MODEL

Current annual HVAC electricity use (kWh) Electricity price (selected currency/kWh) Expected HVAC energy reduction (%) Insulation project cost ($)

Use HVAC energy, not whole-home electricity when possible

Insulation primarily affects heating and cooling loads. If you use whole-home electricity, savings can be overstated because appliances, lighting and electronics may be largely unaffected. For mixed-fuel homes, separate heating fuel from other household energy wherever possible before applying a savings percentage.

How to choose a realistic percentage

Use an energy audit, contractor analysis or calibrated building model whenever possible. Savings depend on existing insulation level, climate, air leakage, duct location, thermostat settings and heating/cooling equipment.

Related guides

See the Building Wall Heat Transfer Calculator for R-value, U-value and multilayer-wall physics, plus Attic Insulation Installation Cost, Spray Foam Insulation Cost and Home Energy Audit Cost.

Insulation savings: avoid treating a generic percentage as measured savings

Reviewed September 14, 2026. Savings depend on climate, existing assembly, air leakage, HVAC efficiency and the part of the envelope actually improved. Use an audit or building model when the investment decision is material; this calculator is best used for transparent sensitivity testing.

DOE Energy Saver: insulation → · Analyze wall heat transfer →