Does a Loft Conversion Necessitate a Planning Permission?


This is a question that most property holders ask themselves when they decide to convert or extend their existing loft area. While planning permission is not required for most loft conversions, a decision not to obtain permission in obligatory cases could be extremely pricey, particularly if the conversion of your attic involves major modification of the roof space. Here is a precise and handy guide to give you an idea about whether or not planning permission is required for your loft conversion.

If your intended loft conversion abides by the following conditions set by the building authority, it is not mandatory to obtain planning permission.

  • There is no change in the height of the roof after conversion
  • Conversion is devoid of any alteration of the roof
  • If your loft is not a segment of a flat or an apartment
  • Conversion does not include extensions or additions beyond the existing roof slope’s plain
  • Loft is not housed within a property on designated land, such as conservation areas, heritage sights or national parks
  • The extension of roof space is within the permissible volumes:
    • 40 cubic meters in the case of terraced houses
    • 50 cubic meters in the case of detached and semi-detached houses
  • Materials used for the attic conversion is in sync with other parts of the building
  • Any of the segments of conversion is not higher than the existing roof’s uppermost portion
  • No terrace, balcony or an elevated platform within the house is chosen for conversion
  • Unless otherwise the side-facing window is 1.7 meters above the converted room’s ground level, it should be non-opening and obscure-glazed
  • Conversion does not affect the existence of protected species like bats

However, the procurement of a planning permission becomes indispensable when your loft conversion demands extensive alteration of the roof space. Take for instance, the case of a dormer conversion, wherein the conversion is done with the installation of a dormer window that projects out from the roof. Another type of loft conversion that entails a permit is Hip to Gable, as it is all about swapping the existing slopping roof with a flat gable wall. Mansard conversions also need a permit primarily due to the complicated roof procedures that form part of its extension.

Precisely, the scope and nature of your loft conversion will usually determine whether you need to obtain planning permission. So make sure that you’re well informed about the Building Control Laws, before you do anything. A knowledgeable loft conversion specialist can also guide you through the confusion of obtaining a permit for loft extension or conversion in your area.