Garden room cost calculator
Pick a size and the extras you want to see the typical price range for a bespoke, insulated garden room in Sheffield.
By Garden Rooms Sheffield. Prices checked October 2026.
A free matching service, not a builder. We find you a local garden room builder. How it works
Typical price
£19,000 to £24,000
12.0 m² floor area
Includes insulation, electrics, double glazing and fitting. A typical range, not a quote.
Get a fixed price for this roomGarden room prices by size
Before extras. Rounded to the nearest £500.
| Size | Floor area | Typical price |
|---|---|---|
| 3 × 2.5 m | 7.5 m² | £12,000 to £15,000 |
| 4 × 2.5 m | 10 m² | £16,000 to £20,000 |
| 4 × 3 m | 12 m² | £19,000 to £24,000 |
| 5 × 3 m | 15 m² | £24,000 to £30,000 |
| 5 × 4 m | 20 m² | £32,000 to £40,000 |
| 6 × 4 m | 24 m² | £38,500 to £48,000 |
What the extras add
| Extra | Typical addition |
|---|---|
| Toilet or shower room | £4,000 to £8,000 |
| Bifold doors instead of sliding or French doors | £1,500 to £3,000 |
| Air conditioning unit (heats and cools) | £1,500 to £3,000 |
| Sloping garden or awkward access | £1,000 to £3,000 |
Where these prices come from
The base range is £1,600 to £2,000 per square metre, from prices published by garden room builders in and around Sheffield, checked in October 2026. Small standard models start from about £10,000.
The extras were checked in October 2026 against national price guides from MyBuilder, MyJobQuote and Summerhouse24, AirCon Adviser's garden room guide and one builder's published price calculator. The ranges for the base price agree with these guides, which put a 12 m² room at about £18,000 to £24,000.
Prices change with materials and each builder's diary, so treat the result as a guide. The builder gives a fixed price after visiting your garden, because the ground, access and cable route all affect the cost. Planning costs, if you need them, are covered in our planning guide.
Cost questions
How much is a garden room per square metre?
Bespoke, insulated garden rooms in Sheffield usually cost £1,600 to £2,000 per square metre built, including electrics and double glazing.
What is the cheapest way to get a garden room?
A smaller, standard size with a flat roof and sliding doors, on a level garden with easy access. Every extra (a bathroom, bifold doors, groundworks) adds to the price.
Does composite cladding cost more than timber?
Not reliably. Price guides show composite and timber rooms at similar prices per square metre, so it depends on the builder and the boards you choose. Ask for both in the quote.
What does the price include?
The ranges assume a fully insulated room with double glazing, electrics run from the house and fitting. They do not include furniture, or a toilet or shower unless you tick it.
Is the calculator a quote?
No. It gives a typical range from prices builders publish. A garden room builder gives a fixed price after visiting your garden, because the ground, access and cable route all affect the cost.
Why does a sloping garden cost more?
The base has to level the room. Ground screws handle gentle slopes cheaply; steeper slopes may need a raised frame, steps or a retaining wall.
Does a garden room add value to a house?
A well-built, insulated room is usually seen as a plus by buyers, especially as a home office. How much it adds depends on the house, the area and the quality of the build.
Get a fixed price for your garden room
Three short steps, about two minutes. The more you tell us, the more useful the builder's first call will be.
We're a free matching service, not a builder. We find a local garden room builder and tell you who they are before anyone contacts you.
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- We'll find a garden room builder who covers your area and tell you who they are, usually within one working day.
- We only pass on your details if you tell us you're happy for us to.
- They then arrange a visit and give you a fixed price. We won't send you marketing.