Old windows are often real energy guzzlers: leaky frames, simple glazing and poor insulation values mean that valuable heating energy is lost. Replacing windows can significantly reduce energy consumption, improve living comfort and save money in the long term. But what costs do homeowners actually incur when replacing windows - and which subsidies help to reduce the investment?
In this article you will learn everything about the Costs for window replacement, current Price examples and Funding opportunities in the year 2025.
The most important facts in brief (TL;DR)
- Cost per window: approx. 500-1.200 € including installation - depending on material and size.
- Total cost of window replacement: for a detached house with 10 windows around 5.000-12.000 €.
- Price factors: Material (plastic, wood, aluminium), glazing, installation effort.
- Promotion: Grants via KfW or BAFA possible - up to 20 % Savings.
- Tip: Compare several offers and combine window replacement with other refurbishments.
Why replacing windows makes sense
Replacing windows is one of the most effective measures for the energy-efficient refurbishment of a building. In older properties in particular, the energy loss through old windows can be considerable - often up to 25 % of the heating energy is lost. New windows with modern insulating glazing and sealed frames significantly reduce this loss.
Energy efficiency and heating cost savings
Probably the most important reason for new windows is the Reduction in energy consumption. Triple-glazed windows with a low heat transfer coefficient (U-value) ensure that heat stays inside and cold stays outside. Depending on the condition of the old windows, the Heating energy consumption by up to 20 % reduce heating costs. This quickly becomes noticeable in the annual heating costs - and protects the climate at the same time.
Increase in the value of the property
In addition to saving energy, replacing windows also increases the Market value of a property. Energetically refurbished buildings achieve better values in the Energy certificate and are much more attractive to buyers or tenants. So anyone planning to sell or rent out their property in the next few years will benefit twice over - through lower ancillary costs and a higher sales price.
More living comfort and sound insulation
New windows not only improve the energy balance, but also the Living comfort. Modern models offer:
- better Sound insulation,
- more Security through burglar-resistant fittings,
- a more pleasant Room temperatureeven on cold days.
This makes them a worthwhile investment in quality of life, security and sustainability.
Replacing windows: Costs at a glance
The cost of replacing windows depends heavily on the material, size, glazing and installation effort. On average, the Total costs per window including installation between 500 and 1,200 euros.
Average window costs by material
| Window material | Price per window (incl. installation) | Properties |
| Plastic windows | approx. 500-800 € | Inexpensive, easy to clean, good thermal insulation |
| Wooden windows | approx. 700-1.000 € | Natural material, good insulation, but more maintenance-intensive |
| Aluminium windows | approx. 900-1.200 € | Very durable, modern, but expensive and less insulating |
| Wood-aluminium combination | approx. 1.000-1.400 € | Elegant design, long service life, top insulation values |
(Prices as of 2025, including installation and standard glazing)
Example calculation for a detached house
For a house with 10 windows Depending on the design, the following guide values result:
- Plastic windows: 5.000-8.000 €
- Wooden windows: 7.000-10.000 €
- Aluminium windows: 9.000-12.000 €
Costs for installation
In addition to the pure window price Installation costs to. These usually amount to 150-300 € per windowdepending on:
- Accessibility of windows (e.g. upper floor, old building)
- Condition of the window reveal
- Cost of dismantling and disposing of old windows
For difficult old building situations (e.g. listed buildings), the Installation costs also up to €400 per window amount.
What factors influence the costs?
The cost of window replacement can vary greatly depending on the building, material and installation conditions. In addition to the window type itself, several Influencing factors a decisive role in pricing.
1. material of the window frame
The material is one of the biggest cost differences:
- Plastic windows are the most favourable and at the same time low-maintenance.
- Wooden windows look high quality, but require regular care.
- Aluminium windows are robust, but significantly more expensive.
- Wood-aluminium windows combine design and durability, but are the most expensive option.
Tip: PVC-U windows with additional steel reinforcement offer good value for money and are ideal for most homes.
2. glazing and thermal insulation value
The U-value (heat transfer coefficient) indicates how well a window insulates.
The lower the value, the better the energy efficiency - but also the higher the price.
- Double glazing: more favourable, but hardly standard today.
- Triple glazing: around 10-20 % more expensive, saves heating costs in the long term.
- Special glazing (sound insulation, safety glass) can increase the total cost by a further €100-200 per window.
3. size and shape of the windows
Large window areas, skylights or special shapes (e.g. arched windows) cause higher costs due to:
- more material usage,
- more complicated installation,
- Possibly customised frames or special glazing.
4. type of installation
The installation effort also influences the total price.
- New building: simple installation in prepared openings - lower labour costs.
- Old building: Additional work such as dismantling, repairing the masonry or adapting the window reveal lead to additional costs.
With Window refurbishment for old buildings are therefore 10-30 % higher costs than is usual for new builds.
5 Regional differences and tradesmen's costs
Labour costs for fitters vary greatly from region to region. In Large cities or conurbations like Berlin, Munich or Hamburg, they are up to 20 % above the national average.
Funding for new windows 2025
Anyone replacing their old windows can in many cases State subsidies use. The aim of these programmes is to Energy efficiency of buildings and reduce CO₂ emissions. In 2025, there will still be attractive Grants and loans about the BAFA and the KfW.
1. BAFA subsidy for individual measures
The Federal subsidy for efficient buildings (BEG) of the BAFA supports window replacement as a so-called Individual measure on the building envelope.
- Funding level: up to 15 % Subsidy on the eligible costs.
- Condition: The U-value of the new windows must be max. 0.95 W/m²K lie.
- Eligible: Costs for materials, installation, planning and disposal of old windows.
💡 Extra tip:
If an additional Energy consultant and the measure is part of an individualised Refurbishment Roadmap (iSFP) the subsidy is increased by another 5 % to a total of 20 % Promotion.
2 KfW loans for energy-efficient refurbishments
As an alternative to the BAFA subsidy, the KfW (Reconstruction Loan Corporation) favourable interest rates Loans with repayment subsidy.
- Programme: "KfW 261 - Residential building loan"
- Prerequisite: The building must achieve a certain efficiency house standard after refurbishment.
- Advantage: Combining several measures (e.g. windows + insulation) increases the amount of funding.
3. tax incentives
If no subsidy is applied for, homeowners can claim the costs against tax:
- 20 % of the refurbishment costsspread over three years,
- max. € 40,000 per property,
- applies to owner-occupied residential buildings.
This option is particularly interesting if no energy consultant has been commissioned or the cost of applying for a subsidy is too high.
4. sample calculation
A homeowner has ten old windows replaced, total cost 10.000 €.
- With BAFA subsidy (15 %): 1,500 € saving.
- With iSFP bonus (20 %): 2,000 € saving.
- Effective investment: 8,000 - and permanently lower heating costs.
Saving tips when replacing windows
New windows are a worthwhile but cost-intensive investment. However, with the right planning and targeted measures, the overall costs can be significantly reduced - without compromising on quality or energy efficiency.
1. compare offers
A common mistake is to obtain only one or two quotations.
💡 Tip: Get at least three comparative offers from qualified specialist companies. Pay attention to:
- the U-value (the lower, the better),
- the Type of glazing (double or triple),
- contained Services (dismantling, disposal, sealing).
A careful comparison can up to 20 % price difference ten windows can quickly add up to more than 1,000 € savings.
2. combine subsidies and tax bonuses
In some cases, the Tax incentives with the BAFA subsidy not directly - but you can check which option is more financially viable.
An energy consultant will help you find the optimum combination of grant, loan and tax bonus.
3. choose the right time
Many window manufacturers offer Low season (autumn/winter) more favourable conditions to fill order gaps. If you plan the installation in good time, you can 5-10 % of total costs save.
4. combine energy-efficient refurbishments
If you already have a Facade insulation or Roof renovation it is worth carrying out the window replacement at the same time.
This saves double the scaffolding costs and enables higher delivery quotas within the framework of a Overall reorganisation plan.
5. pay attention to quality and guarantees
Cheap windows are tempting in the short term, but can be expensive in the long term - for example due to leaks or a lack of guarantees.
Therefore pay attention to:
- CE marking,
- Test certificates for insulation values,
- Installation by a specialised company with warranty.
6. use tax advice
A discussion with a tax consultant can help, Optimum amortisation options or Conveyor combinations especially in the case of rented properties.
Replacing windows in existing properties
Replacing windows in older buildings in particular is an important step towards improving energy efficiency and securing the property value in the long term. However, different conditions often apply to existing buildings than to new builds - both technically and economically.
1. special challenges in old buildings
Additional work is often required when replacing windows in existing buildings:
- Adjustment of the Window reveal to modern frame dimensions,
- Sealing between masonry and window frame,
- Disposal of old wooden or lead frames,
- possibly Monument protection requirements.
This additional work can increase costs by 10-30 % compared to a new build. Nevertheless, the investment pays off in the long term thanks to lower heating costs and a better energy balance.
2. energetic effect in old buildings
New windows are a central component of the energy-efficient refurbishment.
They lower the U-value of the building envelope and thus ensure
- clear Lower heat loss,
- less Draughts,
- a more constant indoor climate.
If the window replacement with a Façade or roof insulation combined, the overall energy rating of the property is improved - a clear plus point in the energy performance certificate.
3. influence on the property value
Replacing windows not only increases the quality of living, but also the Market value of a property.
Modern, energy-efficient windows are an important argument for buyers and tenants - especially in cities like Berlin, where energy efficiency is increasingly a decision criterion.
Tip: If you would like to know the current value of your house or flat after the refurbishment, you can carry out a Professional property valuation be carried out.
Professional implementation and management
Replacing a window is more than just replacing old frames - it is a Technically demanding construction projectwhich requires precise planning, coordination and professional execution. Relying on experienced partners here saves time, costs and hassle.
1. why professional planning is crucial
Important questions should already be clarified in the planning phase:
- Which window sizes and types suit the building?
- Which U-values are useful for energy efficiency and promotion?
- What is the ideal sequence for several refurbishment steps?
An experienced specialist company or energy consultant will help you select the right windows, apply for subsidies correctly and avoid typical installation errors.
2. quality features of professional installation
You can recognise a good assembly by the fact that:
- All joints Airtight and thermal bridge-free are sealed,
- the window stress-free is installed,
- all transitions between the window frame and the wall are cleanly finished.
Incorrect installation can otherwise lead to Mould formation, draughts or leaks and thus to follow-up costs that are easily avoidable.
3. management and maintenance
After installation, windows should be regularly checked and maintained:
- Check seals for elasticity,
- Lubricate fittings,
- Clean the drainage openings.
This maintains the full function and insulating effect for decades.
4. support from a property management company
Particularly in the case of apartment blocks or rented properties, it is worth working with an experienced Property management.
She coordinates tradespeople, monitors the schedule and ensures smooth implementation - even if there are several parties in the building.
Conclusion: Replacing windows pays off in the long term
Replacing old windows is an investment that pays off on several levels.
Energy-efficient models not only reduce heating costs, but also increase living comfort and the value of the property. Thanks to state subsidiestax benefits and professional planning, window replacement also remains financially manageable.
Anyone modernising their windows now will benefit twice over:
- through noticeable energy savings in everyday life
- and through a Sustainable increase in value of his property.
With the right partners at your side - from energy consultants to property managers - the project can be realised efficiently and stress-free.
Deutsch 
English (UK)