Insulation Energy Savings

Estimate energy and cost savings from a U-value improvement, area, and your own climate and price assumptions.

What current and improved U-values mean

A U-value describes heat flow through one square metre of an element per kelvin of temperature difference. A lower value means less transmission heat loss. The calculator uses only the difference between your current and proposed U-values and adds no regional building requirement.

How to use the calculator

Select a currency and enter the element area that will actually be improved.
Enter the current and expected new U-values.
Use heating degree days from an appropriate local source.
Add your energy price and the heating system's seasonal efficiency.

Energy and cost savings example

For 100 m², an improvement from 1.20 to 0.30 W/m²K, and 3,000 heating degree days, calculated useful transmission loss falls by 6,480 kWh per year. At 90% system efficiency that represents 7,200 kWh of purchased energy. Multiplying by an example input of 0.10 per kWh produces an annual cost estimate of 720.

Thermal bridges, moisture, and workmanship

Thermal bridges, air leakage, solar and internal gains, occupant behavior, and changing weather are not modeled separately. An unsuitable assembly or poor installation can create moisture damage. This estimate does not replace an energy assessment, moisture review, or energy certificate. Use the related material calculator for board or roll quantities.

Frequently Asked Questions

What does a U-value show?

It describes heat flow through one square metre of an element per kelvin of temperature difference. A lower U-value means less calculated transmission heat loss.

How does insulated area affect the result?

Savings rise proportionally with the area actually improved in this model. Subtract windows, doors, and sections that will not be insulated.

What are heating degree days?

Heating degree days summarize the duration and intensity of heating demand over a year. Use a value from an appropriate local source instead of a generic country average.

How does energy become cost savings?

The calculator divides avoided useful heat by system efficiency and multiplies the resulting purchased-energy estimate by your price per kWh.

Are thermal bridges and ventilation losses included?

No. The formula considers only the entered U-value improvement over the area. Assess thermal bridges, air leakage, and ventilation separately.

Why do moisture and workmanship matter?

Material, assembly, junctions, and airtightness affect moisture safety and actual performance. Have critical constructions reviewed by a qualified professional.

Why does this not replace an energy assessment?

An assessment covers the whole building, local climate data, systems, moisture, workmanship, and required documentation. This calculator provides only a user-defined scenario.