Before you buy a shed or plans, check whether you need permission. In England the Planning Portal sets out the permitted development limits for outbuildings. In the US it depends on your city or county, and we show one town as an example only.

This guide is based on the public sources listed at the end. We have not tested the products or services mentioned.

England: the Planning Portal limits

An outbuilding is generally permitted development if:

  • It is single storey, with eaves up to 2.5 m and an overall height up to 4 m with a dual-pitched roof, or 3 m with any other roof.
  • Within 2 m of a boundary, the whole building is no higher than 2.5 m.
  • Together with extensions and other buildings, it covers no more than half the land around the original house.
  • It is not forward of the wall forming the principal elevation of the original house.

Designated land is stricter. In national parks, the Broads, AONBs and World Heritage Sites, buildings more than 20 m from the house are limited to 10 square metres in total, and in designated land buildings at the side of a property need permission. Any outbuilding in the curtilage of a listed building needs planning permission. These allowances do not apply to flats or maisonettes.

Building regulations are separate from planning. We did not verify them for this guide, so ask your council.

United States: check locally

Rules are set by city or county. As an example only, the Sudbury, Massachusetts building department says sheds of 200 square feet or less and up to 16 feet long need no building permit, and gives setbacks for small and larger sheds. That is one town. Search your own city or county site for "accessory structure" and ask about size, height, setbacks, utilities and any HOA rules.

Before buying plans or a kit

Match the footprint and height to the local limits before you buy materials. See our guide to what to check in woodworking plans.

Last checked: 15 October 2026. Sources: Planning Portal, outbuildings: planning permission; Town of Sudbury, MA building department, do I need a permit to erect a shed.