Cost calculator
What a garden room costs
Set the size, the specification and any extras to see a typical price range for a bespoke, insulated garden room. Figures checked October 2026 by Garden Rooms Harrogate.
Typical price
£28,000 to £35,000
17.5 m² floor area
Plan to scale. Includes base, insulation, electrics, glazing and fitting. A typical range, not a quote.
Begin an enquiryPrices by size
Before extras, rounded to the nearest £500. Most Harrogate enquiries fall between the second and fifth rows.
| Size | Area | Standard | Higher |
|---|---|---|---|
| 3.5 × 2.8 m | 9.8 m² | £15,500 to £19,500 | £19,500 to £25,500 |
| 4 × 3 m | 12 m² | £19,000 to £24,000 | £24,000 to £31,000 |
| 5 × 3.5 m | 17.5 m² | £28,000 to £35,000 | £35,000 to £45,500 |
| 5 × 4 m | 20 m² | £32,000 to £40,000 | £40,000 to £52,000 |
| 6 × 4.5 m | 27 m² | £43,000 to £54,000 | £54,000 to £70,000 |
| 7 × 5 m | 35 m² | £56,000 to £70,000 | £70,000 to £91,000 |
What the extras add
| Extra | Typical addition |
|---|---|
| Shower room with WC and basin | £4,000 to £8,000 |
| Kitchenette (sink, worktop, under-counter fridge) | £3,000 to £7,000 |
| Bifold or large sliding glazing in place of French doors | £1,500 to £3,000 |
| Sedum (green) roof | £1,500 to £3,000 |
| Air conditioning (heats and cools) | £1,500 to £3,000 |
| Slope, tree roots or awkward access | £1,000 to £3,000 |
What moves the price
Floor area sets most of the cost, which is why the calculator starts there. After size, five things decide whether a room lands at the bottom or the top of its range.
The glass
Glazing is the most expensive part of the walls. A pair of French doors and one window is the baseline. A wall of sliding or bifold doors adds £1,500 to £3,000, and frameless or floor-to-ceiling glass moves a room into the higher specification band.
The base and the ground
A level lawn with firm ground takes ground screws or a simple slab. Slopes, soft ground, tree roots or rock add £1,000 to £3,000. In Harrogate, where many gardens have mature trees and some sit on clay, screws are common because they avoid cutting roots.
Access
If materials can come down the side of the house on a barrow or a small dumper, labour stays normal. If everything has to be carried through the house or over a wall, allow for an extra day or two of labour, sometimes more.
Distance from the house
Power, data and water come from the house in a trench. A room 10 m from the back door is cheap to connect. At 30 m or more, the armoured cable is thicker, the trench longer and the drainage harder, which can add £1,000 or more.
Cladding and roof
Composite and softwood cladding cost about the same. Cedar, thermally modified timber and charred larch cost more but last longer and suit stone houses. A flat roof is the cheapest; a sedum roof adds £1,500 to £3,000, and a pitched roof adds height that may take the room outside permitted development near a boundary.
Costs beyond the room
A few costs sit outside a builder's price. They are easy to forget when setting a budget.
- Planning application: £528 for a householder application in England (2025 fee), only if the room is not permitted development. A certificate of lawful development, which confirms a room does not need permission, costs half the application fee.
- Building regulations: usually not needed under 15 m², or under 30 m² if the room is at least 1 m from the boundary or built of non-combustible materials. Annexes and new drainage always need approval; fees vary by council.
- Landscaping: a path, a step or decking at the door, and making good the lawn after the trench. Often £500 to £3,000.
- Furniture and blinds: rarely included, and worth budgeting for in a room with a lot of glass.
The full rules are in our guide to planning in Harrogate.
Where these figures come from
Room prices are typical UK prices from published price lists of bespoke garden room builders that we reviewed in October 2026: £1,600 to £2,000 per m² standard and £2,000 to £2,600 per m² higher specification, including VAT. Extras come from the same review. They are national figures rather than Harrogate-only prices. Planning fees and building regulations limits are from:
Cost questions
How much does a garden room cost?
A bespoke, insulated garden room typically costs £1,600 to £2,000 per square metre built, including electrics, double glazing and fitting. A 4 × 3 m room is about £19,000 to £24,000; a 5 × 4 m room about £32,000 to £40,000.
How much is a garden room per square metre?
£1,600 to £2,000 per m² for a well built, insulated room, and £2,000 to £2,600 per m² for a higher specification with frameless glass, hardwood cladding or a more complex roof.
Are garden rooms more expensive in Harrogate?
Building costs are close to the national picture. What tends to raise Harrogate budgets is the houses themselves: larger gardens lead to larger rooms, conservation areas and listed houses push towards better materials, and mature trees often mean screw foundations.
What is included in the price?
The ranges cover the base, frame, insulation, roof, cladding, double glazing, interior lining, flooring, electrics from the house and fitting. Furniture, landscaping, planning fees and any bathroom or kitchenette are extra.
How can I keep the cost of a garden room down?
A compact size with a flat roof, French or sliding doors, on level ground with side access and a short cable run. Each of those choices keeps you in the lower half of the range.
Do garden rooms add value to a house?
A well built, insulated room is generally seen by buyers as a useful extra, especially as a home office. How much it adds depends on the house, the garden it takes up and the build quality.
Do I need to pay VAT on a garden room?
Yes, at the standard rate, if the builder is VAT registered. Check whether the price you are given includes it; the ranges here assume it does.
Further reading
- Garden offices
Sizes and running costs.
- Garden annexes
Why they cost more per square metre.
- Rooms with a bathroom
Drains, pumps and prices.
Begin an enquiry about your room
Three short stages, a couple of minutes in all. Tell us about the garden and what the room is for, and we will find a builder in your part of North Yorkshire who designs and builds rooms like it.
Free to use, and we do not build anything ourselves. We name the garden room builder we have in mind before anyone contacts you.
Thank you. Your enquiry has arrived.
- We will find a garden room builder who works in your area and tell you who they are, usually within one working day.
- Your details go to them only once you have said you are happy for us to pass them on.
- They arrange a visit and give you a fixed price. You will not get marketing from us.