Most garden greenhouses in England do not need planning permission. A greenhouse counts as an outbuilding, and outbuildings fall under permitted development as long as they stay within a set of limits. The rules below come from the Planning Portal guidance on outbuildings. They apply to houses in England. Wales, Scotland and Northern Ireland have their own rules, so check with your council there.
This page sums up official guidance. It is not legal advice. If you are unsure, ask your local planning authority before you build.
The permitted development limits
Your greenhouse needs planning permission if it breaks any of these limits:
- Not in front of the house: no outbuilding on land forward of the wall that forms the principal elevation (usually the front of the house).
- Single storey only.
- Eaves no higher than 2.5 m.
- Overall height: no more than 4 m with a dual-pitched roof, or 3 m with any other roof.
- Near a boundary: within 2 m of the boundary of your property, the whole building may be no higher than 2.5 m.
- No platforms: no verandas or balconies, and no raised platform higher than 0.3 m.
- The 50% rule: outbuildings, extensions and other additions may not cover more than half of the land around the "original house". That means the house as first built, or as it stood on 1 July 1948 if it is older.
What this means in practice
The 2 m boundary rule is the one that catches greenhouses. Most garden greenhouses stay under 2.5 m tall, but some large models go over:
- Palram Canopia Glory 6x8: 2.69 m to the ridge
- Halls Magnum 8x10: 2.58 m
- Rhino Premium 8x10: 2.54 m
Under permitted development, these models must stand more than 2 m from your boundary. Closer than that, you need planning permission. Check the height of the base too, because a base plinth adds to the total.
Where the rules are stricter
- Designated land: in National Parks, the Broads, Areas of Outstanding Natural Beauty, conservation areas and World Heritage Sites, an outbuilding at the side of the house needs planning permission.
- National Parks, the Broads, AONBs and World Heritage Sites: buildings, enclosures, containers and pools more than 20 m from the house are limited to 10 m² in total.
- Listed buildings: any outbuilding within the grounds of a listed building needs planning permission.
- Flats and maisonettes: permitted development rights for outbuildings do not apply. The same goes for houses where an Article 4 Direction has removed the rights.
Lean-to greenhouses
A lean-to fixed to the wall of your house is not a detached outbuilding, so the outbuilding rules above do not cover it. Check the extension rules on the Planning Portal or ask your council before you build. More in the lean-to greenhouse guide.
Building regulations
Planning permission and building regulations are separate. According to the Planning Portal, an outbuilding usually does not need building regulations approval if:
- its floor area is under 15 m² and it contains no sleeping accommodation, or
- its floor area is between 15 m² and 30 m², it contains no sleeping accommodation, and it stands at least 1 m from any boundary or is built substantially of non-combustible materials.
Almost every garden greenhouse falls under 15 m². An 8x10 ft greenhouse covers about 7.4 m².
Before you build
- Look up whether your property is listed or in a conservation area. Your council's website shows this.
- Check your deeds and any rules from a landlord or management company. They can be stricter than planning law.
- Measure the distance to the boundary and add the base to the height.
Sources: Planning Portal guidance on outbuildings (planning permission and building regulations pages). Back to the buying guide.
