Window subsidies in 2026: BAFA, KfW, and tax benefits explained simply
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Why replacing windows in 2026 is particularly worthwhile
If you want to keep your property efficient, comfortable, and stable in value in the long term, 2026 is a particularly good time to replace your windows—for several compelling reasons:
New windows with triple glazing and optimized frames significantly reduce energy loss, which noticeably lowers your heating costs and significantly increases the energy efficiency of your home.
Thanks to improved thermal insulation, you consume less heating energy—this automatically leads to lower CO₂ emissions and supports climate protection goals for the coming years.
With energy prices remaining high, replacing your windows will protect you from high heating costs in the long term and ensure that your energy costs remain predictable.
The Building Energy Act is gradually tightening minimum energy standards. Modern windows easily achieve the required U-values, whereas older models struggle to do so.
Windows remain eligible for subsidies—regardless of whether you are planning a single measure or part of a larger renovation project. Grants and loans can be combined to reduce your investment costs.
Energy-efficient windows increase the level of modernization of your home, thereby enhancing its appeal and resale value. Buyers are paying increasing attention to energy efficiency ratings.
Modern windows keep out street noise, cold, and heat much better—making your living environment quieter, more balanced, and more pleasant.
New glazing reduces solar heat gain and keeps rooms noticeably cooler even on hot days, without your air conditioning having to work harder.
Security fittings, reinforced frames, and modern glazing protect your home much better against attempted break-ins than old windows.
As energy regulations are likely to become even stricter in the coming years, early renovation will save you from having to carry out more costly retrofitting work later on.
What subsidies are available in 2026 for new windows and window replacement?
To help you plan your renovation project optimally, here is a clear overview of all relevant subsidies for window replacement in 2026. These include subsidies, loans, and tax benefits based on the subsidy guidelines set annually by the Federal Ministry for Economic Affairs and Climate Protection (BMWK) and provided by BAFA and KfW.
Application: must be submitted before the start of the project
Building age: existing buildings approx. 5 years old or older are eligible for funding
Funding rate: 15% subsidy on eligible expenses
Funding cap: up to €60,000 per residential unit (with iSFP)
Technical requirements: Windows must achieve defined U-values (e.g., Uw ≤ 0.95 W/m²K)
Combination: Limited combination with other programs possible (no double funding for the same measure)
Increased subsidy through the iSFP bonus
With an individual renovation roadmap (iSFP), you can further increase your window subsidy:
Bonus: +5% additional subsidy on BAFA measures
Maximum subsidy: subsidy increases to up to 20%
Eligible costs: Increase in the eligible amount from €30,000 to up to €60,000 per residential unit
Prerequisite: Creation by an energy consultant before the start of measures
Advantage: Particularly useful for extensive renovation strategies
KfW programs for energy-efficient buildings and individual measures
KfW offers low-interest loans for comprehensive energy-efficient building renovations and individual energy-saving measures such as windows:
Relevant program: Loan 261 (“Residential Building Loan”)
Financing: low-interest loans with long terms
Application: via bank or financing partner
Eligible measures: replacement of windows, doors, and other building components
Combination: possible with grants, but no double funding for the same measure
Tax relief under Section 35c of the German Income Tax Act (EStG)
For owner-occupied properties, you can claim tax relief for energy-efficient renovation measures—including windows:
Relief amount: up to 20% tax reduction over three years
Distribution: 7% in year 1; 7% in year 2; 6% in year 3
Prerequisite: owner-occupied residential building, year of construction irrelevant
Costs: materials and labor are deductible
Exclusion: cannot be combined with BAFA or KfW for the same measure
Regional subsidy programs and grants
Many federal states and municipalities offer their own subsidy programs that can be used in addition to federal funds:
Federal states: Subsidies e.g. in Baden-Württemberg, Hesse, Saxony, Bavaria
Type of subsidy: Grants, low-interest loans, or bonus programs
Combination: Often combinable with BAFA/KfW (depending on guidelines
Requirements: vary depending on region (income, age of building, energy consultant requirement)
Advantage: can significantly increase the total funding
Requirements and conditions for funding
To successfully obtain funding for window replacement, you must meet all technical, formal, and organizational requirements—only then will you receive grants or loans. All technical and organizational requirements for window replacement are specified in the current BMWK guidelines. Implementation is carried out by BAFA and KfW.
This ensures that the renovation measures meet political and technical objectives:
New windows must meet defined minimum energy efficiency values, e.g., a Uw value (total heat transfer of the window) of no more than 0.95 W/(m²K) for KfW individual measures, in order to ensure the required thermal insulation. You can find more details on eligible U-values in our guide “Eligible U-values: Which windows meet the BEG requirements?”
For BAFA individual measures, your building must be at least 5 years old, calculated from the date of the building application or building notification.
The window replacement must be carried out by a recognized specialist company – DIY work is not eligible for funding.
Installation standard: Installation should be carried out in accordance with RAL guidelines or comparable quality standards in order to guarantee airtightness and energy savings.
For BAFA measures, the involvement of an energy efficiency expert (EEE) is mandatory – they will assist with planning, application, and acceptance.
To qualify for funding, you need product identifiers such as TPB-ID and TPN-ID, which clearly document technical data and U-values.
Manufacturer documentation with details of Uw values, g-values, frame profiles, and installation instructions must be provided in full.
Detailed documentation of the installation (e.g., photos, reports, test reports) is often part of the subsidy requirements.
Payments must be made by bank transfer so that BAFA and KfW can clearly track the costs. In addition, the contractor's invoice must show all eligible items separately.
An energy consultant confirms that replacing the windows will result in an “energy improvement” – purely cosmetic upgrades are not eligible for funding.
Some programs give preference to windows made from sustainable materials such as recyclable PVC, FSC/PEFC wood, or environmentally friendly insulation materials.
The subsidy application must be submitted before the contractor's contract is signed – a later application will automatically result in rejection.
Many programs require a minimum amount of eligible costs (e.g., $2,000 to $5,000).
Once approved, measures must usually be completed and verified within 24 months.
Not all subsidies can be combined – BAFA, KfW, and tax subsidies, for example, cannot be used simultaneously for the same measure.
Separate requirements and, in some cases, different technical limits apply to listed buildings.
Applying for window subsidies: step by step
To successfully obtain subsidies for window replacement, it is important that you prepare your application carefully—from scheduling and documentation to combining programs.
Step 1 – Choose the right time to submit your application
Before you sign a contract or order materials, you must submit your funding application. For grants (e.g., BAFA) and loans (e.g., KfW), the application must be submitted before the start of the project. Therefore, always plan the funding first and only then commit to a start date for your renovation.
Step 2 – Involve energy consultants and specialist companies
The next step is to commission someone from the list of energy efficiency experts compiled by dena (German Energy Agency) – the central point of contact for specialists in energy-efficient construction and renovation. This person will review the planned measures, draw up an individual renovation roadmap (iSFP) if necessary, and confirm the energy efficiency of the window replacement. At the same time, a qualified specialist window construction company is selected to carry out the installation. This ensures that both the technical requirements and the funding criteria are fully met.
Step 3 – Compile quotes and documents
Now you ask the selected contractor to provide you with a detailed quote – ideally with a postponement clause that expressly states that the order is subject to the approval of the subsidy. In addition, you collect all the necessary technical documentation: U-value certificates for the windows, product data sheets, information on frames, glazing, and, if applicable, sun protection. The contact details and identification of your energy expert are also among the documents you need for the application.
Step 4 - Submit your complete funding application
With your energy consultation, quote, and technical documentation, you can now proceed to the actual application process. Submit your data online to the BAFA and provide details about your building, the planned measures, and your energy efficiency expert. For KfW loans, you submit the application via your house bank or a financing partner, who will fill out the subsidy bank documents together with you. Once the measures have been completed, the TPB ID and TPN ID as well as the final evidence (e.g., invoices, installation reports) are also submitted to the BAFA so that the payment can be made.
Step 5 – Check the combination of subsidies and document the implementation
Before you start, you should check with your energy consultant and bank whether subsidies (BAFA), loans (KfW), and tax incentives under Section 35c of the German Income Tax Act (EStG) can be combined in a meaningful way—because not every combination is permitted for the same measure. Once the approvals have been granted, the specialist company can begin with the installation. It is important that you file all invoices, reports, and technical documentation neatly so that you have them to hand for the final documentation, any queries from the funding agency, or your tax return.
Subsidy examples and calculation examples
Below you will find practical examples that show you how subsidies and cost savings can have a concrete impact when replacing windows:
Example 1: Replacing old windows in an existing building
Imagine you want to replace 10 old windows with new, energy-efficient windows with a U-value of no more than 0.95 W/(m²K). The total cost is €25,000. With the BAFA basic subsidy of 15%, you can get €3,750 back. If you also opt for an individual renovation roadmap (iSFP), the subsidy rate increases to up to 20% – and you will receive a subsidy of €5,000.
Example 2: Complete renovation to KfW Efficiency House standard
If you are planning a comprehensive renovation to bring your building up to the Efficiency House standard (including window replacement), KfW can offer you a low-interest loan of up to €150,000 per residential unit. Depending on the level of renovation, you will receive an attractive repayment subsidy of up to 45%, for example.
Example 3: Tax reduction for personal contributions
If you finance the window replacement entirely from your own funds, you can instead take advantage of the tax bonus under Section 35c of the German Income Tax Act (EStG). Spread over three years, you can deduct up to 20% of your costs from your taxes—this is particularly worthwhile if you have a higher tax burden and is also suitable for owner-occupiers.
Which types of windows are eligible for subsidies?
Want to know which types of windows are eligible for subsidies and loans? We provide a clear overview of all eligible systems—including variants that are often overlooked. This is based on the current subsidy conditions of BAFA and KfW for 2026, which specify exactly which types of windows and technical requirements are recognized for government subsidies and loans.
Eligible windows:
Durable windows with multi-chamber profiles, triple glazing, and thermally insulated edge seals easily achieve Uw values of ≤ 0.95 W/m²K and are therefore particularly eligible for subsidies.
Frames made of solid wood or laminated wood offer excellent insulation values and are well suited for energy-efficient renovations; they often meet the requirements of BAFA and KfW and are popular in sustainable construction.
Modern aluminum frames with thermal breaks also achieve the required Uw values; they are ideal for high stability, large glass surfaces, or modern architecture.
Combination models with wood on the inside and aluminum on the outside combine very good insulation with long durability and are considered particularly subsidy-friendly, e.g., for passive house or KfW standards.
Hybrid frames with a plastic core and aluminum cover shell offer good insulation performance with a modern look; they are often used in energy-efficient building renovations and meet the required Uw limits.
Specially certified windows with extremely low Uw values (0.60 to 0.80 W/m²K) are considered particularly eligible for subsidies and are suitable for demanding renovation projects
Wooden or wood-aluminum windows that are historically appropriate may also be eligible for subsidies, provided they meet minimum U-values; in the case of historic buildings, this is usually assessed on a case-by-case basis by energy consultants and historic preservation authorities.
Windows with increased sound insulation are also eligible for subsidies if they also meet the minimum energy efficiency requirements (e.g., class 4 to 5 with triple glazing).
Glazing with a reduced g-value is eligible for subsidies provided that the Uw-value is complied with – e.g., for skylights or south-facing windows.
Energy-optimized roof windows with triple glazing also meet the subsidy criteria, provided that the Uw value and installation quality comply with the specifications.
Windows with burglar-resistant glazing (RC2/RC3) are eligible for subsidies if they meet the energy requirements—security and efficiency must be combined.
Now with Salamander myWindow for optimal window subsidies in 2026
Choose window systems from Salamander myWindow and benefit from modern technology, low U-values, and perfect conditions for attractive subsidy programs:
High energy efficiency thanks to innovative multi-chamber profiles and high-performance triple glazing
Best subsidy opportunities thanks to excellent U-values, ideal for BAFA, KfW, and tax subsidies
Sustainable materials and high recyclability for an environmentally conscious home
C3 principle for optimal window selection: location, building, and usage data are incorporated into your perfect solution
Modern, sleek design with floor-to-ceiling elements and optional aluminum look
Comprehensive service from consultation and planning to professional installation
Greater living comfort thanks to better insulation, soundproofing, and a pleasant indoor climate
Active climate protection thanks to resource-saving production and durable, sustainable systems
Start now with Salamander myWindow for an energy-efficient home and secure all the financial benefits. Your specialist partner will guide you through the optimal subsidy strategy and help you choose the perfect window solution for your needs!
FAQ – Frequently asked questions about the 2026 window subsidy
Do you have questions about the 2026 window subsidy? Here you will find the most important answers to help you take advantage of the right subsidy and meet all the requirements.
Subsidies will be available for individual measures relating to the building envelope, i.e., the replacement or initial installation of windows, exterior doors, and external sun protection systems such as roller shutters. These measures are part of the federal subsidy program for efficient buildings – individual measures (BEG EM) and are therefore eligible for subsidies.
The basic subsidy from the BAFA amounts to approximately 15% of the eligible costs. If you include an individual renovation roadmap (iSFP), you can receive an additional bonus of 5%, i.e. up to 20% in total. KfW offers high loan volumes with attractive repayment subsidies for complete renovations, depending on the efficiency house level achieved.
Private owners, homeowners' associations, municipalities, and other legal entities are eligible to apply. Among other things, you will need a quote from a specialist company, proof of energy efficiency, product data sheets for the windows, and, if applicable, documentation from the energy consultant (e.g., TPB/TPN).
The application to BAFA must be submitted online before the measure begins. For KfW loans, the application is made through your bank, and here too, the rule is: first the application, then the project. You can simply claim the tax bonus under Section 35c of the German Income Tax Act (EStG) on your income tax return—even retroactively if the windows have already been installed.
The windows should have a maximum Uw value of approximately ≤ 0.95 W/(m²K) to be eligible for funding. Installation must be carried out professionally, airtight, and with certified quality. Professional installation and sealing work is essential for the subsidy to be approved.