Loft conversions

Planning Permission

New regulations came into force on 30 September 2013 which changed the building work which can be done without needing to apply for planning permission. The Welsh Government has produced a technical guide, and a householder guide, available here, to help you understand how permitted development rules might apply to your circumstances.

Planning permission is not normally required. However, permission is required where you extend or alter the roof space and it exceeds specified limits and conditions.

A loft conversion for your house is considered to be permitted development, not requiring an application for planning permission, subject to the following limits and conditions:

  • If you live in a terraced house your extension must be less than 40 cubic metres or in any other case less than 50 cubic metres
  • You may not build a loft extension beyond the plane of the existing roof slope on the principal elevation of the dwellinghouse
  • The roof extension cannot be higher than the highest part of the existing roof
  • Other than for hip to gable enlargements, any roof extension  must be at least 20cm from the eaves of the existing roof
  • The materials used in your roof extension must match, as much as possible, the appearance of the existing dwellinghouse.  UPVC will not be acceptable, other than possibly for windows.  Loft extensions are expected to be finished in hanging tiles, render or brickwork to match your house
  • Windows within 10.5 metres of a boundary on the side elevation of a roof slope will need to be obscure-glazed or non-opening, to protect the privacy of your neighbours
  • A Juliet balcony with no platform, which does not project from the roof extension by more than 300mm, and is not within 10.5 metres of any boundary opposite the side elevation of the house, would be permitted.  Any other form of balcony, roof terrace or veranda will require planning permission
  • Hip to gable extensions are permitted
  • Roof extensions are not permitted in conservation areas, national parks, areas of outstanding natural beauty or World Heritage Sites, and you must seek planning permission to build them
  • If the building is listed you should consult with your local planning authority

Disclaimer - Wales

This is an introductory guide and is not a definitive source of legal information. This guidance relates to the planning regime for Wales. Policy in England may differ. If in doubt contact your Local Planning Authority.

Read the full disclaimer here.