Thermal Modernisation Relief Calculator 2026

The thermal modernisation relief (ulga termomodernizacyjna) is a deduction from taxable income for energy-efficiency expenditure on a single-family residential building. It is available to owners and co-owners of such buildings who file under the progressive tax scale, the flat income tax, or the lump-sum tax on recorded income. The building must already be completed and in use.

The cap is PLN 53,000 per taxpayer. If spouses are co-owners of the building and file separate tax returns, each may deduct up to PLN 53,000. The limit is cumulative across all thermal modernisation projects undertaken by the taxpayer.

If the relief exceeds the taxpayer's income in the year the costs were incurred, the unused portion may be carried forward for up to 6 subsequent tax years. This gives a total of 7 years (the year of expenditure plus 6 more) to fully use the deduction.

Qualifying costs are listed in a regulation issued by the Minister of Investment and Development. They include heat pumps, solar PV systems, condensing gas boilers, wall and roof insulation, external window and door replacement, and mechanical ventilation with heat recovery. The full list covers more than 60 types of materials and services.

You need VAT invoices issued by active VAT-registered sellers or contractors. Receipts from non-VAT entities do not qualify. Keep all invoices for 5 years from the end of the tax year in which you filed the return, as the tax office may request them during an audit.

Yes, but only the portion of costs not covered by the grant is eligible for the relief. The grant amount must be subtracted from the qualifying expenditure before calculating the deduction. Your own contribution above the grant amount qualifies in full.

At the full PLN 53,000 cap and the 12% rate the tax saving is PLN 6,360. At the 32% rate the saving rises to PLN 16,960. Under the flat 19% tax, the maximum saving is PLN 10,070. The calculator computes the saving automatically based on your income.

Enter the deduction on form PIT/O (an attachment to PIT-37, PIT-36 or PIT-28). In the Twój e-PIT pre-filled service you can add it before confirming the return. Enter the total qualifying expenditure from your VAT invoices, capped at PLN 53,000.

No. The thermal modernisation relief applies only to owners or co-owners of single-family residential buildings. Flats in multi-family buildings, tenements and co-operative housing units are not eligible. The building must already be built and in use.

The thermal modernisation project must be completed within 3 years from the end of the tax year in which the first expenditure was incurred. If the deadline is missed, the taxpayer must repay all previously deducted amounts plus statutory interest, and report this in the tax return for the year in which the deadline expired.