As the UK experiences record-breaking temperatures this summer, many homeowners are seeking relief by installing air conditioning units, often assuming that planning permission is not required. However, John Van-Eker, principal planning consultant with Planning Portal's Planning Guidance Service—a joint venture between the Ministry of Housing, Communities and Local Government and TerraQuest—warns that this assumption is a widespread misconception that could lead to serious consequences.
Planning Permission Required for Air Conditioning Installation
Van-Eker explains: "Because of widespread misinformation online, homeowners may not realise that they actually need to submit an application for planning permission to install an air con unit – potentially landing them in hot water if they didn't receive approval." While permitted development rights allow certain home improvements without planning permission, installing an air conditioning unit is not covered. Homeowners must apply to their local authority and wait up to eight weeks for approval—a lengthy wait during a heatwave.
Risks of Unauthorized Installation
Installing a permanent air conditioning system without permission constitutes a planning breach, even if unintentional. Homeowners may be required to submit a retrospective application. If this is rejected, the council can issue an enforcement notice demanding removal. Defying the notice is illegal and could lead to prosecution. Additionally, selling a property with an unauthorized unit can complicate the sale, as sellers must demonstrate that all necessary approvals were obtained. Without them, they may need to either submit a retrospective application or remove the unit entirely.
Exceptions and Alternatives
If a home already has a permanent air conditioning unit and needs a like-for-like replacement, no new application is required. However, upgrading to a larger or more powerful unit requires a new application via the Planning Portal website. Van-Eker also notes that recent changes to permitted development rights in May 2025 have made it easier to install heat pumps, which can both heat and cool a building year-round. "Misinformation online can easily mislead homeowners into thinking a project is covered by permitted development, when it actually requires an application for planning permission," he adds. He recommends consulting an expert or using a verified planning provider like Planning Portal's Planning Guidance Service before making any home improvements.
