Planning permission is not normally required to turn two properties into one by knocking through a party wall provided the changes are internal and do not impact the external appearance of the property.

You should check with your local planning authority that they agree, and there are not any previous planning changes or conditions which may have an impact.

Additional permissions may be required depending on the building’s history and their location. If the building is listed, an application for listed building consent will be required before any major changes are made to the dwellings.

The work will have to comply with building regulations, the focus will be on structural work and safety.

‍Read more about how building regulations apply to internal walls.

When you, or an agent acting on your behalf, have submitted a planning application, the local authority will firstly check the application to check if it’s complete. This validation process allows the authority to ensure everything that is required to decide an application has been received and provided correctly. They will contact you if they require any further information from you.

After the application has been validated, the determination process begins and takes up to 8 weeks for smaller applications, or up to 13 weeks for larger applications. The authority should be able to give you an idea about the likely timetable. The local authority will contact you with their decision.

Read more about the decision-making process for planning applications.

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Raising your garden level a small amount is likely to not require planning permission as it is likely to have minimal impact on the chances of flooding or overlooking your neighbours.

Increases of over 30cm may require planning permission as a significant change can impact drainage or your neighbours. If the changes are close to a boundary, you should consider whether it will overlook your neighbours or be intrusive.

You should contact your local planning authority to understand whether your proposed changes will require planning permission.

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There is no single legal definition of "habitable room", as its use and meaning are subject to context. Generally, a habitable room is a space in a building that is designed for people to live, sleep, or spend extended periods of time in, but does not include bath or toilet facilities, corridors or utility rooms.

Significant changes to insulation and thermal elements would normally require building regulations approval. The extent to which this applies depends on the existing insulation and what it will be replaced with.

If the work is completed by a member of a competent persons scheme, then an application for approval will not be required.

Find out more about insulation and building regulations on our common projects.

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