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Residential annexes

Before you begin your planning, we recommend reading our practical advice on home improvements.

Residential annexes (or granny annexes) are developments that allow relatives to live with their family independently.

When you need permission

Planning permission is needed:

  • to build an annex, not attached to the main house, within your property boundary
  • for any new building to provide an annex associated with a flat
  • when there are conditions attached to a previous planning approval preventing development

You may also need permission under building regulations legislation.

When you don't need permission

Permission is not typically needed when you want to convert a residential out building, such as a shed or garage, within the property boundary, when there will be no kitchen or cooking facilities

Policy requirements

Planning applications for residential annexes must comply with the following North Somerset Council policies:

  • Sites and policies plan – part 1 development management - policy DM43
  • Replacement local plan - policies H7, H8 and RD3
  • Core Strategy - policies CS32, CS33, CS10 and CS11
  • Residential design guide standards
  • Parking standards supplementary planning documents

Statement of use

When sending us your application for an annex, you must include a statement to show:

  • who will use the annex
  • the user’s relationship to the occupants of the main house
  • how the use of the annex will meet our policies

Help and advice

Before building your annex, we recommend you employ an accredited agent and use our pre-application advice service to ensure you have the correct permissions.