Building an additional storey on to your house is considered to be permitted development, subject to certain limits and conditions. An application for the local authority’s prior approval will also be required.

‍

The permitted development allowances described here apply to houses and not to flats and maisonettes.

Building regulations approval is required to add additional storeys to an existing building to make it into a liveable space. The regulations will need to be adhered to in terms of structural strength, stability, stairs, sound insulation, fire safety and ventilation.

‍