Extending Existing Business Premises

Minor extensions to business premises, including the erection of additional buildings within the curtilage, may not need a planning application because the development is already permitted under Schedule 2 to the Town and Country Planning (General Permitted Development) Order 1995. The guidance below indicates when, in general, an application for permission will or will not be required.

Factory or warehouse extensions

Planning permission will not normally be required if your extension is:

1. less than 1000 sq m of floor space or 500 sq m in areas of special control of floor space; and
2. less than 25 per cent of the volume of the original building; and
3. below the height of the original building.

The extension must be related to the current use of the building or the provision of staff facilities.

Planning permission will be required if the extension:

1. materially affects the external appearance of the building; or
2. comes within five metres of the boundary of the site; or
3. reduces the amount of space available for parking or turning of vehicles.

Volume is calculated from external measurements.'Original' means as first built, or as the building stood on 1 July 1948, if built before then. The allowance is once and for all; any previous enlargement of the building counts against these freedoms.