Do Garden Domes Need Building Regulations Approval?

Building regs vs planning: not the same thing

First, clear up the common confusion:

• Planning permission is about whether you can put the structure there (size, siting, your property type). Most domestic garden domes are permitted development and don't need it, but check with your local planning authority, especially for listed buildings, conservation areas and sites near a boundary (see our planning permission guide).
• Building regulations are about how a building is built: structural safety, insulation, fire, drainage, ventilation. They apply mainly to habitable buildings and certain works.

You can need one without the other, so it's worth checking both rather than assuming.

When a dome generally doesn't need building regs

Used as a typical, non-residential garden room (somewhere you work, exercise, relax or pursue a hobby), a garden dome usually sits outside building regulations, much like many sheds, summerhouses and garden offices of comparable size. It's an ancillary garden structure, not a dwelling, which is the key distinction.

In England, a detached, single-storey outbuilding with no sleeping accommodation is usually exempt if its floor area is under 15 m². From 15 m² to 30 m² it's exempt only with extra conditions, for example standing at least 1 m from the boundary. Here's where each size sits:

Rules differ in Scotland, Wales and Northern Ireland, so check with your local building control there.

When building regs can come into play

There are situations where they may apply, and it's important to be straight about them:

• Sleeping or living accommodation. This is the big one. The exemption only covers outbuildings with no sleeping accommodation, so the moment a garden building is used as habitable space (a bedroom, an annexe, somewhere someone lives or regularly sleeps), building regulations typically apply. A dome is a garden room, not a dwelling, as our guide to living in a garden dome explains.
• Size and proximity. Bigger buildings, or ones close to a boundary, can fall within scope: for a dome, that means a Large less than 1 m from the boundary.
• Electrics, drainage and plumbing. Mains power to a garden building falls under Part P in England and Wales, so use a registered electrician, with outdoor-rated fittings and RCD protection (see our electrics guide). Drainage or plumbing work can bring its own regulations into play.
• Wood burners. Installing a stove brings building regulations into scope. Fit one only through a HETAS-registered installer, with a proper flue, the clearances they specify and a carbon monoxide alarm; our wood burner guide explains what's involved.
• Commercial or public use. A dome used commercially (a venue, a let unit) may face additional requirements, and commercial use usually needs planning permission too.

Because these depend on the detail of your project and local interpretation, they're exactly the kind of thing to check rather than guess.

What to actually do

• For normal garden-room use: you'll usually be fine, but a quick confirmation with your local building control removes any doubt, especially for a Large close to a boundary.
• For sleeping, living, annexe, commercial or serviced use: speak to building control (and your planning authority) and take professional advice before you commit. Don't treat a garden dome, or any garden building, as a dwelling without going through the proper process.

A reputable supplier will always point you to the right checks rather than wave the question away, which is what we're doing here.

Frequently asked questions

Source: the exemptions for small detached buildings in Schedule 2 of the Building Regulations 2010 (England).