Outbuildings, Sheds and Garages: Do You Need Planning Permission?

The permitted development rules for garden buildings, sheds, garages, summer houses and other outbuildings in England.

Garden buildings are a popular way to create extra storage, workspace, or leisure space. Most outbuildings can be built under permitted development rights, but the rules on size and positioning matter.

What Counts as an Outbuilding?

For permitted development purposes, outbuildings include:

Sheds and workshops
Garages and car ports
Summer houses and garden rooms
Greenhouses
Swimming pools and tennis courts
Saunas and hot tub enclosures

Permitted Development Rules for Outbuildings

You can build an outbuilding without planning permission if all of these conditions are met:

Height Limits

Within 2 metres of a boundary: maximum height 2.5 metres
Dual-pitched roof (apex/gable): maximum height 4 metres
Any other roof type (flat, mono-pitch): maximum height 3 metres

Size and Position

Must not be built forward of the principal elevation (i.e. not in front of the house)
Total area of all outbuildings must not cover more than 50% of the curtilage (the total garden area around the house, excluding the original building footprint)
Must be single storey - no upper floors, galleries, or sleeping platforms above ground level
Must be used for purposes incidental to the enjoyment of the house - storage, hobbies, home gym, etc.

Designated Areas

In conservation areas, national parks, AONBs, the Broads and World Heritage Sites:

Outbuildings to the side of the house are not permitted development
Total outbuilding area must not exceed 10 square metres (rather than 50% of the garden)

Can I Use an Outbuilding as a Home Office?

Yes, using a garden building as a home office is generally considered incidental to the dwelling and is permitted. However, you cross a line if:

You employ staff who commute to work in your garden building
Clients or customers regularly visit
The building becomes the primary commercial premises of a business

In these cases, it could be considered a change of use requiring planning permission.

Can I Live in an Outbuilding?

No. Using a garden building as a self-contained dwelling (bedroom, living space with cooking facilities) is not permitted development. It would require planning permission for a new dwelling, which is unlikely to be granted in most back gardens.

Garages

A detached garage follows the same outbuilding rules. If you want to convert an existing integral garage into a room, this is usually permitted development as it is an internal alteration. However, if you change the garage door to a window or wall, this alters the external appearance and may need permission in conservation areas.

Building Regulations

Small detached outbuildings (under 15 square metres floor area with no sleeping accommodation) are generally exempt from building regulations. Between 15 and 30 square metres, they are exempt if they are at least 1 metre from a boundary or built of non-combustible materials. Above 30 square metres, building regulations will apply.

Tips

Measure your total outbuilding coverage before building - include existing sheds and garages
Check your property's title deeds for any restrictive covenants that might prevent outbuildings
If near a boundary, be considerate to neighbours - even if you do not need permission
Get a Lawful Development Certificate for larger or more valuable garden buildings to protect your investment