How is responsibility for renovating windows in condominium ownership regulated?

Windows as joint property

In Switzerland, windows are mandatory common parts in accordance with Art. 712b of the German Civil Code, as they determine the external appearance of the building. The decision on a complete replacement is therefore up to the owners' meeting. While maintenance (such as oiling the fittings) is usually the responsibility of the individual owner, many regulations in 2026 regulate that the costs of replacing the windows are borne directly by the respective beneficiary of the apartment, provided that a uniform material is chosen.

Classification as a common component

Since windows form the border between the private sphere and the public outside world, they are a functional part of the building envelope. If each owner were to install windows according to their own taste, the architectural concept of the property would quickly be destroyed. For this reason, the Community has a dominant right of participation in 2026 when it comes to the type, the frame color and the type of glazing. In the worst case scenario, an unauthorized exchange without a decision by the Community may result in the owner having to carry out the dismantling at his own expense.

However, this communal character also serves to protect the individual. Since windows form part of the static and thermal envelope, the Community is responsible for ensuring that these components fulfil their protective function. If, for example, masonry is damaged due to leaky window frames, this is a problem for the entire co-owner association. Responsibility for the renovation is therefore usually coordinated centrally by the property administration to ensure that the work is carried out professionally and in accordance with cantonal energy laws.

Distribution of costs and the role of regulations

Although the windows are communal, many communities deviate from the classic distribution key according to value ratios when it comes to payment. The regulations often state that each owner must bear the costs of the windows of his own unit himself. This model has the advantage that owners who treat their windows with care do not have to pay for premature wear in other apartments. However, it requires a clear distinction between normal maintenance and comprehensive renovation of the entire façade.

In practice in 2026, this individual cost transfer often means that renovations are carried out in stages. Nevertheless, the community must ensure that the energy quality of the house does not suffer from a “patchwork”. If the majority of owners decide on a comprehensive energy-efficient renovation, for example in order to receive subsidies from the building program, individual owners must comply with this majority decision, even if they then have to bear the costs for their windows themselves in accordance with the regulations.

Energy requirements and subsidies 2026

In 2026, the GEAK (cantonal building energy certificate) and the associated thermal insulation requirements will play a central role in window renovation. Modern triple glazing is now standard in order to meet strict cantonal energy regulations. Since windows account for a significant portion of heat loss, their renovation is often the first step towards a better energy class for the entire property. The community must plan strategically, as funding often only flows if the entire building envelope or at least a large part of it is renovated at the same time.

Decision-making in the meeting requires tact. Since window replacement is usually a necessary or useful structural measure, there are different quotas for voting. While necessary repairs can be decided with a simple plus, useful measures that increase the value of the property or significantly improve energy efficiency usually require qualified more. Coordinating these interests is one of the main tasks of modern administration in order to maintain the value of the property in the long term.

Conclusion: Uniform image despite individual use

Responsibility for window renovation in condominiums is a balancing act between Community law and individual cost obligations. Windows are part of the façade and are therefore subject to the decision-making power of the community, even though the bill often ends up directly with the individual owner.

In summary, anyone who wants to renovate their windows in 2026 must go through the owners' meeting and check the regulations for specific cost rules. Good preparation involving energy consultants and administration is the key to overcoming both the legal hurdles and the technical requirements for a modern, energy-efficient home. The windows are not only your view of the outside world, but also an essential part of the collective value of your property.

glossary

• building envelope: The entirety of all components that close off a building from the outside, such as the roof, façade and windows.
• Value ratio: The share of a residential unit in the total value of the property entered in the land register, decisive for voting rights.
• Qualified More: A voting mode that requires the majority of people and at the same time a majority of the ratings.
• GEAK: The cantons' official building energy certificate, which assesses the energy quality of the building envelope and building services.
• Compulsory joint: Components that cannot legally belong to the special right due to their importance for the safety or appearance of the house.