Loft Conversion Permitted Development

Since the changes were made to planning law in Oct 2008 it is very likely that your loft can be converted under permitted development. Planning will only be required under certain circumstances (see planning). Permitted development is the best way to maximizing your potential space as planning permission will usually mean some constraints on the size of your conversion. The following states the conditions for permitted development:

  • The house is a single family dwelling and not a flat or maisonette
  • The proposed extension or dormer window should not be raised above the highest part of the roof
  • The slope of any part of the roof, which faces a highway, must not be extended.
  • Dormers can be built on the rear and the hipped side when the slope of any part of the roof, do not face a highway. A ‘hip to gable’ conversion is also permitted in the same circumstances.
  • The proposed loft conversion exceeds 40 cubic meters in the case of a terraced house or 50 cubic meters in any other case. (This is volume added externally with dormers etc.)

In cases where work can be done under permitted development, a ‘certificate of lawful development’ may be obtained prior to commencing the project.

Certificate of Lawful Development

These can be obtained from the local authorities and are not planning applications. The purpose of these certificates is to ensure that your proposed extension or conversion is within your permitted volume. Plans will need to be submitted to the local authority, who will check and confirm in writing the legitimacy of the proposed work. These can take approximately 6 weeks but are not a legal requirement.