Summers are getting hotter and hotter – and with them, the desire for air-conditioning in one’s own flat is growing. In its judgement of 17 July 2026 (Case No. V ZR 162/25), the Federal Court of Justice (BGH) ruled that flat owners may, in principle, request the installation of a split air-conditioning system with an outdoor unit. In future, a flat owners’ association (WEG) may no longer reject such a request across the board.

What was the case about?

In the case in question, a family wished to mount the outdoor unit of a split air-conditioning system on the external wall of their balcony. This required drilling into the façade. The owners’ association refused to grant consent, citing, amongst other things, potential noise, condensation, heat emission and damage to the façade.

However, the Federal Court of Justice (BGH) made it clear that, when deciding whether to grant consent, the immediate structural impact of the measure is the decisive factor. Potential disruptions caused by subsequent operation, such as noise or heat generation, are not in themselves sufficient grounds to refuse consent.

Consent possible subject to conditions

However, the ruling does not amount to a free pass. The owners’ association may make its consent subject to reasonable technical and design requirements, for example regarding:

proper installation,
sound insulation,
condensation drainage,
aesthetic design, and
compliance with public-law requirements, such as those relating to the protection of listed buildings.

What does this mean for property owners?

For flat owners, the ruling provides greater planning certainty. Anyone wishing to install a split air-conditioning system can, in future, invoke a fundamental right to consent. The owners’ association must examine each application individually and may not reject it without objective grounds.

Nevertheless, it is advisable to prepare the application carefully and to submit technical documentation, details of the mounting arrangements, and information on sound insulation and condensation drainage at the outset. This often helps to avoid potential queries or disputes within the owners’ association.

Conclusion

With this ruling, the Federal Court of Justice strengthens the rights of flat owners and takes account of the growing demands of modern living. At the same time, it remains possible to guide the installation through sensible technical and design specifications. In future, the focus will no longer be on blanket objections, but on the assessment of the specific individual case.

Source: Federal Court of Justice, judgement of 17 July 2026 – Ref. V ZR 162/25.