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Planning Permission

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.

Under new regulations that came into effect from 1 October 2008 a loft conversion for your home is considered to be permitted development, not requiring an application for planning permission, subject to the following limits and conditions:

  • A volume allowance of 40 cubic metres for terraced houses
  • A volume allowance of 50 cubic metres for detached and semi-detached houses.
  • No extension beyond the plane of the existing roof slope of the principal elevation that fronts the highway.
  • No extension to be higher than the highest part of the roof.
  • Materials to be similar in appearance to the existing house.
  • No verandas, balconies or raised platforms.
  • Side-facing windows to be obscure-glazed; any opening to be 1.7m above the floor.
  • Roof extensions not to be permitted development in designated areas*.
  • Roof extensions, apart from hip to gable ones, to be set back, as far as practicable, at least 20cm from the eaves.


*Designated areas include national parks and the Broads, Areas of Outstanding Natural Beauty, conservation areas and World Heritage Sites.

Common projects: Loft Conversion

Building Regulations

Building regulations approval is required to convert a loft or attic into a liveable space.

Read more about building regulations relating to loft conversions.


Protected Species

Work on a loft or a roof may affect bats. You need to consider protected species when planning work on this type. A survey may be needed, and if bats are using the building, a licence may be needed.

• Contact Natural England for more advice.
• View specific information regarding Bats (PDF 33Kb)

Disclaimer: this is an introductory guide and is not a definitive source of legal information. Read the full disclaimer here.

NOTE: This guidance relates to the planning regime for England. Policy in Wales may differ. If in doubt contact your Local Planning Authority.