Replacing roof windows under the Clean Air programme – what can be funded?

An old roof window can be the biggest heat leak in the whole attic. The good news is that its replacement can be funded from the Polish Clean Air programme (Czyste Powietrze) – partly, and for households with the lowest incomes even in full. The bad news: the grant is not paid "just for the window". You need to meet several conditions, and the new model must have the right parameters. We explain how it works after the changes that came into force on 20 July 2026.

1. Can you get a grant for roof windows at all?

Yes. In the programme, roof windows are treated the same way as vertical windows and doors – as joinery whose replacement improves the energy efficiency of the house. The grant covers both the purchase of the window and its installation.

There is one condition, but a very important one: window replacement must be part of a thermal modernisation project and must result from an energy audit carried out before the work starts. If the auditor decides the windows need replacing, they are included in the scope of work – and only then do they count towards the grant.

2. Who is eligible?

The programme is aimed at owners and co-owners of single-family houses and of separate units within them that have their own land and mortgage register. It does not cover multi-family buildings. The key conditions:

• the building was put into use before 1 January 2021,
• the new windows are installed in heated rooms – a window in an unused, cold loft does not count,
• you have owned the property for at least 3 years – with exceptions (e.g. inheritance, acquisitive prescription, and from 20 July 2026 one year is enough if you bought at least 50% of the shares or received them as a gift from your parents or grandparents),
• you fall within one of the three income thresholds (below).

Three funding levels

3. Which roof window meets the requirements?

This is where mistakes happen most often. What counts above all is the heat transfer coefficient Uw of the whole window – not of the glass alone (Ug), which manufacturers often highlight in their advertising.

• Roof windows: Uw no higher than 1.1 W/(m²·K).
• Vertical windows and balcony doors: Uw no higher than 0.9 W/(m²·K).
• The window must be brand new and have a declaration of performance stating its Uw.
• Unlike heat pumps or boilers, windows do not have to be on the ZUM list (Green Devices and Materials).

Roof windows have one more catch: manufacturers state Uw for a specific configuration – the glazing unit, and sometimes the flashing as well. Two windows from the same series but with a different glazing unit can have different parameters. That is why, before purchase, we always check the documents for exactly the variant that will go on the roof.

"In the FAKRO and VELUX ranges, most windows with triple glazing fall within the 1.1 limit. But "most" is not "all" – so before a customer submits the paperwork, we check the parameters of the specific model and size."

You may come across articles online claiming that the 0.9 limit applies to all windows, including roof windows. The requirements for roof windows are, however, less strict, which follows from the Polish technical regulations (WT 2021). Even so, confirm the value that applies to your application in the audit and with the programme operator – they are the ones who settle the grant.

4. How much can you get?

The grant for windows is calculated per square metre, not per unit. The programme sets two limits at once: a percentage of the invoice (40, 70 or 100%) and a maximum rate per m². The lower of the two amounts is paid out.

From 20 July 2026, the rates for windows went up by 10%. For applications submitted from that date they are:

Example

You replace one 78×118 cm window, and the invoice for the window with flashing and installation comes to PLN 3,000. At the basic level, 40% of the invoice is PLN 1,200, but the per-metre limit is approx. PLN 486 – so you will receive approx. PLN 486. At the highest level, 100% of the invoice is PLN 3,000, but the per-metre limit cuts the payout to approx. PLN 1,215.

The takeaway? With roof windows, which are small but relatively expensive to install, the per-m² limit almost always "wins" over the percentage. The grant genuinely lowers the cost, but rarely covers all of it. It is worth knowing this before you plan your budget. Remember too that the total grant for the whole thermal modernisation has a ceiling – at the highest level it is PLN 83,000.

5. How does it work step by step?

• Energy audit. The auditor assesses the house and specifies the scope of work. If the roof windows are in poor condition, they will be included.
• Application. You submit it online (via gov.pl or the application generator of your regional environmental fund) or with the help of an operator at your municipality. For pre-financing and the highest funding level, the operator's assistance is mandatory.
• Selecting and ordering the windows. We select a model with the right Uw and check the documents. You can read the dimensions from the rating plate of the old window, and for an unusual opening it is worth ordering a measurement.
• Installation. The new window is installed together with the flashing and insulation materials. Careful, thermally sound installation matters – a poorly fitted window with a good Uw will still let the cold in.
• Settlement. To settle the grant you need invoices, a work acceptance report and documents confirming the window parameters. After the whole project is completed, an energy performance certificate is also required.

If you use pre-financing (part of the grant goes to the contractor before the work is finished), from 20 July 2026 you have 180 days to complete the work instead of 120.

6. The most common mistakes

• Buying windows before the audit and application. It is safest to start work only once you have the audit and have submitted the application – otherwise you risk the expense not being accepted.
• Checking Ug instead of Uw. The glass-only figure looks great, but the grant is based on the whole window.
• A window in an unheated room. Replacing a window in a cold loft will not be an eligible cost.
• No documents for the specific variant. The declaration must relate to the model and glazing unit actually installed.
• Counting on a percentage refund. With small windows, the per-m² limit decides – plan your budget with a margin.

7. What about the thermal modernisation tax relief?

If you do not qualify for the grant or do not want to go through the whole procedure, there is still the thermal modernisation relief in Polish personal income tax (PIT). The regulations explicitly list windows, including roof windows, together with installation systems and the replacement service. The two forms of support can be combined – but not for the same expenses. Under the relief you can only deduct the part of the costs you paid from your own money.

Summary

Roof window replacement can be funded from the Clean Air programme if it results from the audit, the house meets the programme conditions and the new window has a Uw no higher than 1.1. The grant amount depends on income and window area – for a typical roof window it ranges from several hundred to over a thousand zloty per unit. You can read more about the programme itself, the thresholds and the application path on our Clean Air programme page.

As of September 2026. The rules of the Clean Air programme are updated regularly – before applying, check the current regulations at czystepowietrze.gov.pl or with the operator in your municipality. This article is for information only and does not replace advice from an auditor or programme adviser.