All timber buildings are subject to planning provisions rules: but the majority of buildings don’t require it
Consideration must be given as to the area the building is located; is it an area of Area of Outstanding Natural Beauty (AONB), or similar, and is there adjacent property listed.
As long as certain criteria are met, your building will be classed as a ‘Permitted Development’ and therefore planning permission will not be needed.
The heights and sizes allowed without planning permission
Garden buildings that are considered to be allowed by Permitted Development and do not need planning permission:
- If less than 2m away from the boundary have to be 2.5m or less in height
- If more than 2m away, the building can be 4m to the ridge height on an apex building, or no more than 3m on a flat roof building.
- Buildings in your garden should not take up more than 50% of the total area
- The building should be used for domestic use ie a Granny Annex


Other considerations
If the building is to be over 30 square metres in floor area, or is required for domestic usage, building regulations will be required. Stables and Farm Buildings are exempt.
Your local planning office can give you guidance if you are unsure and equally Independent Building Regulation advisors can detail the specification that is needed