Building regulations for cabins and granny annexes UK

Garden Summerhouse cabin designed and built by Life Space Cabins

Don’t get confused between planning permission (including permitted development) and building regulations.


The first looks after the permission to build whilst the other is responsible for ensuring that buildings are safe and fit for purpose i.e. checking that the building is thermally efficient, structurally sound etc.

We’ve put together information on building regulations for cabins and granny annexes


Building control is separate to planning and you must check if you need approval before you construct or change buildings in certain ways.

The following information was taken from If you are in any doubt give your local Building Control (normally accessed via your Local Authority) a call and they will confirm.

Cabins are likely to come under Class 6 – Small Detached Buildings. In short if you or someone else plans to sleep in the cabin then yes your cabin will need to have Building Regulations. Unless…

  • The cabin is a detached single storey building and has a floor area that does not exceed 30m2, which contains no sleeping accommodation and is a building—
    •  No point of which is less than one metre from the boundary of its curtilage; or
    • Which is constructed substantially of non-combustible material.
  • A detached building, having a floor area that does not exceed 15m2, which contains no sleeping accommodation.


This page aims to promote an awareness of the route through planning and building regulations for a smaller space, but it is not intended to constitute advice. Every effort is made to ensure that the information is correct at the date of publication and to avoid any statement which may mislead. However, no duty of care is assumed to any person and no liability is accepted for any omission or inaccuracy.

Always seek specific professional advice.

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