Replacing old windows is one of the most effective measures for energy-efficient renovations - especially when remodelling existing properties. New windows not only save energy and heating costs, but also significantly improve living comfort. But many homeowners don't realise this: Anyone planning to replace their windows can take advantage of extensive state subsidies. In particular via programmes from the KfW (Reconstruction Loan Corporation) and the BAFA (Federal Office of Economics and Export Control) can apply for grants or low-interest loans - provided that certain technical and formal requirements are met.
In this blog article, you will find out which funding programmes are currently relevant, which technical requirements must be met and how you can proceed strategically when applying in order to receive the maximum amount of support.
Why get funding at all?
The energy-efficient refurbishment of properties is a central component of the German climate protection strategy. Because new windows can significantly reduce energy consumption - often by up to 20-25 % of the heating requirement - the state supports such measures with attractive subsidies.
Advantages of the promotion:
- Reduction of investment costs
- Faster amortisation of the measure
- Better financing options (e.g. low-interest loans)
- Increase in property value
- Demonstrable energy savings for future buyers or tenants
Which funding programmes are eligible?
1. BAFA grants for individual measures (BEG EM)
BAFA promotes window renovations as part of the programme „Federal funding for efficient buildings - individual measures“ (BEG EM for short). This subsidy applies to both owner-occupied and rented residential properties.
Funding level:
- 15 % Subsidyon the eligible costs
- +5 % bonusif an individual renovation roadmap (iSFP) is available
Maximum eligible costs: 30,000 per residential unit (corresponds to a grant of up to €6,000)
Important: The application must before placing the order be placed!
2nd KfW loan 261 for refurbishment to an efficiency house
Anyone who not only replaces individual measures such as windows, but also renovates the entire house to make it more energy efficient (e.g. façade, roof, heating), can apply for a loan from KfW. 261 „Residential buildings - credit“ request.
Conditions:
- Low-interest loan of up to €150,000 per residential unit
- Repayment subsidiesbetween 5 % and 45 % - depending on the efficiency house standard achieved
- Also applies to owners' associations and property developers
Prerequisite: It must be a certified Energy efficiency expert who accompanies and documents the measure.
What technical requirements must windows fulfil?
For windows to be eligible for subsidies, they must have certain energy properties - particularly with regard to the U-values (heat transfer coefficient).
BAFA requirements for windows eligible for subsidies:
- Maximum U-value of 0.95 W/m²K
- Windows must be professionally DIN 4108-2be installed
- Verification by energy efficiency experts (e.g. through technical project verification)
Attention: Only the following are eligible Windows with thermal insulation glazing - Simple insulating glass windows are not enough.
Tips on how to apply: How to get funding
1. plan and apply at an early stage
Subsidies are available only if the application is submitted in good time - i.e. before the craftsman's business is commissioned or the work is started. This is the most common mistake that leads to rejection.
2. involve energy consultants
For almost all funding programmes, a Authorised energy efficiency expert necessary. This is created:
- iSFP (individualised refurbishment roadmap)
- Technical project description (TPB)
- Confirmation after realisation
Tip: On the website www.energie-effizienz-experten.de you will find qualified specialists in your region.
3. check the combination of funding programmes
In many cases, the Combine BAFA subsidy with KfW loans or tax write-offs. Some federal states and local authorities also offer supplementary programmes.
Example: In Berlin, the Investitionsbank Berlin (IBB) offers further grants for energy modernisation.
4. carefully document offers and evidence
The following documents are required for funding:
- Offer with detailed description of the windows (incl. U-value)
- Proof of the energy consultant
- Invoices after realisation
Photos before/after the renovation
Calculation example: Window renovation with BAFA subsidy
A homeowner would like to replace 12 windows with a U-value of 0.9 W/m²K. The total costs amount to €18,000.
- Subsidy from BAFA: 15 % = € 2,700
- With iSFP bonus: +5 % = 900 €
- Total grant: € 3,600
This reduces the net investment to 14.400 € - with simultaneous energy savings of up to 20 %.
Conclusion: Efficient window renovation with planning and funding
Replacing old windows pays off - not only in terms of energy efficiency, but also economically. Clever use of state subsidy programmes can significantly reduce investment costs. It is particularly important to Foresighted planning, The involvement of qualified specialists and compliance with minimum technical standards such as the U-value.
If you subsidise, you save twice: energy and money. And creates a home that is not only more comfortable, but also more sustainable.
Checklist: Replacing windows with a subsidy - step by step
| Step | Description of the | Done |
| 1 | Find an energy consultant and make an appointment | ☐ |
| 2 | Analyse existing windows and clarify requirements | ☐ |
| 3 | Have a refurbishment roadmap drawn up (optional) | ☐ |
| 4 | BAFA or KfW application before commissioning place | ☐ |
| 5 | Obtain offers with technical details (incl. U-value) | ☐ |
| 6 | Await approval and award contract | ☐ |
| 7 | After refurbishment: collect invoices and evidence | ☐ |
| 8 | Final documentation by energy consultant | ☐ |
| 9 | Await payment of the grant | ☐ |
| 10 | Enjoy energy savings and comfort | ☐ |
