Yes, it is possible to build an extension without planning permission from the governing local authority. Such an extension is classed as a “permitted development”. These tend to be small extensions. A homeowner is usually entitled to build up to six metres (eight metres if the house is detached) without planning permission.
However, there are requirements that must be met, as follows:
- Not more than 50% of the surrounding land can be covered by other buildings.
- The extension cannot be forward elevation or side elevation in front of a highway (public/private road/established way on land).
- The extension cannot be higher than the highest part of the roof.
- Single storey extensions cannot go beyond the rear wall of the original building by more than eight metres.
- Single storey extensions cannot exceed the maximum height of four metres.
- Extensions with more than one storey cannot go beyond the rear wall by more than three metres.
- Two storey extensions cannot be closer than 7 metres to the rear boundary of the house.
- Balconies, verandas or raised platforms are not allowed.
- The property is a house and not a flat.
- The house has not been extended since 1948.
- The house is not a listed building or located within a protected area such as an Area of Natural Outstanding Beauty (AONB).
It is highly recommended to seek professional advice by speaking to the relevant local authority or a property solicitor to confirm whether an extension would be classed as a permitted development.