How much does a garden room cost?
Garden rooms are priced by floor area and spec. Enter the size below for an indicative fitted estimate.
What a garden room includes
- 1Base and structure
A level, load-bearing base (ground screws or a slab), then an insulated timber-frame structure.
- 2Weathertight and glazed
Cladding, roof, and doors/windows to a spec that suits year-round use.
- 3Fit-out
Insulation, electrics (and sometimes plumbing/heating), plus internal finish and decoration.
A garden room adds usable space (office, studio, gym) without the disruption of an extension, and photographs well on a resale. It rarely counts as a bedroom, so weigh its value against a loft or extension where you need habitable rooms.
Garden room costs (indicative, fitted)
| Size | Use | Indicative cost |
|---|---|---|
| 9 m² | Compact office | £13,500 – £27,000 |
| 12 m² | Office / studio | £18,000 – £36,000 |
| 18 m² | Room + storage | £27,000 – £54,000 |
| Per m² (fitted) | — | £1,500 – £3,000/m² |
Insulated, glazed, wired and decorated on a prepared base. Usually permitted development within limits.
Frequently asked questions
How much does a garden room cost?+
A fitted garden room typically costs £1,500–£3,000 per m², so a 12 m² office/studio is roughly £18,000–£36,000 including insulation, electrics and finish on a prepared base.
Do I need planning permission for a garden room?+
Garden rooms are often permitted development within size and height limits, provided they're not for sleeping accommodation. Check the limits (and any Article 4 restrictions) for your property.
Related tools & guides
Want to know how these figures are calculated? See our cost methodology.
Cost figures shown are indicative estimates, not quotations. You are responsible for verifying all costs (obtain contractor quotes) and any figures submitted to a lender. ScopeWise is a documentation tool, not financial, tax, structural or planning advice. HMO compliance prompts are guidance only — confirm requirements with your local council, as standards and licensing vary by authority.