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.

Whether raising the height of an external door requires planning permission depends on the location of the door, location of the property and how drastic the height change will be.

For smaller changes to the side and rear of the property, permitted development rights may apply, meaning no application or planning permission is required.

Where the height change will be substantial and have a significant impact on the building’s appearance, planning permission is likely to be required. Especially in cases where the door to be heightened is on the principal elevation of the property.

‍Principle elevation - The most visible or prominent side of a structure, typically facing a street or public area. While often considered the 'front' of the building, it may not always contain the main entrance.

In designated areas such as conservation areas, or on listed buildings you may require additional approvals such as listed building consent.

If you believe permitted development rights apply to a small change, you can apply for a lawful development certificate to ensure this is the case.

Building regulations

Building regulations approval will likely be required where the change impacts the structure of a building, this primarily occurs when an opening is widened. When altering walls you may want to consult a structural engineer.

In most cases, yes - planning permission is required to operate a business from your garage. This is because the use would no longer be purely domestic, and the garage would be considered to have changed use from residential (Class C3) to a business-related use, which requires planning consent.

You typically will not need planning permission to install a hot tub in your garden, as it is classed as an outbuilding and within the permitted development rights in terms of size and portability. However, you may need planning permission if you live in a listed building or conservation area, you should check first with your local authority.

The hot tub will need to adhere to the building regulations in terms of safe and adequate electrical installation by a registered competent person. Find out more about using a registered competent person.

Also, if the hot tub is placed within a building such as a large shed-style structure, there will be separate planning and building control limitations on that structure.

Yes, under permitted development, a new dormer must not be higher than the existing highest part of the roof. It should also have materials that are in similar appearance to the existing roof. Additional limits apply in conservation areas and on listed buildings. Read about planning permission for loft conversions on Planning Portal