A garden room in the UK costs between £15,000 and £50,000 in 2026, with most fully-installed, year-round builds landing around £25,000 to £38,000. Measured by floor area, that’s roughly £1,200 to £2,500 per square metre, rising higher in London and for bespoke designs. This guide explains what moves the price, the costs that headline figures leave out, and what you actually pay installed.
Treat the broad ranges as typical 2026 market figures; treat VeltHaven’s prices as fixed, all-in totals including VAT and installation.
Comparing a garden room against a garage? See our overview of what a garden building costs.
How much does a garden room cost? (Quick answer)
| Specification | Typical UK price per m² | A ~20–25 m² room |
|---|---|---|
| Budget / kit (DIY base & finish) | £1,000 – £1,400 | £15,000 – £28,000 |
| Mid-range, professionally installed | £1,400 – £2,000 | £28,000 – £40,000 |
| Premium / bespoke / London | £2,000 – £2,700+ | £40,000 – £55,000+ |
On top of the building, the costs people most often forget are foundations (£1,500–£5,000), the electrical connection, VAT, and internal finishes. A “from” price that excludes those isn’t the price you’ll pay.
What drives the cost of a garden room
1. How finished it arrives: shell vs turnkey
This is the biggest variable. A weather-tight insulated shell is the lowest price, but you then fit out the floor, power, lighting and decoration yourself. A move-in-ready or turnkey room costs more but arrives finished (floor, electrics, lighting and heating done), so the quote is close to the spend. Decide which you want before comparing prices, or you’ll compare two different things.
2. Size
More floor area costs more, but the per-m² rate usually falls as the room gets bigger because fixed costs (delivery, base, the glazed front) spread further. A 30 m² room is rarely 50% dearer than a 20 m² one.
3. Insulation and glazing: the year-round factor
A summerhouse and a year-round garden office look similar and cost very differently. Genuine year-round use needs proper insulation (we use 100mm PIR walls and roof) and good glazing. A triple-glazed sliding glass wall is a premium feature that lifts both the experience and the price. But it’s the difference between a room you use in January and one you don’t. (How warm is a garden room in winter?)
4. Heating and cooling
A shell has none. Adding efficient heating and cooling (for example a Daikin heat-pump system) is what makes a garden office comfortable in winter and summer, and adds to the cost. On a VeltHaven garden room, a Daikin system is included with the Executive package; with Core or Signature you can have it quoted and added later, by VeltHaven or your own installer.
5. Foundations, electrics and access: the “hidden” costs
- Base / foundations: every garden room needs a level, load-bearing base, commonly £1,500–£5,000 depending on your ground and access.
- Electrical connection: a dedicated supply run from your consumer unit by a qualified electrician.
- Delivery and access: getting the building and materials to the bottom of the garden.
The sensible approach is to assess these from photos of your site before you commit. That’s how VeltHaven quotes the base and any extra electrical work, so they’re agreed up front, not sprung on installation day.
What a VeltHaven garden room costs
VeltHaven garden rooms are sold at one fully-installed price including VAT and delivery, in three sizes and three packages — Core, Signature and Executive. The building is identical across the three; the package simply decides how much of the interior we finish before handover. The base/groundwork and any extra electrical connection are quoted separately from your site photos.
| Model | Size | Core | Signature ★ | Executive |
|---|---|---|---|---|
| ATLAS | 5 × 4 m · 20 m² | £26,950 | £32,950 | £38,950 |
| NOVA ★ | 5 × 5 m · 25 m² | £31,950 | £38,450 | £44,950 |
| APEX | 6 × 5 m · up to 30 m² | £36,950 | £43,450 | £49,950 |
All prices are fully installed, including VAT and delivery. What each package includes:
- Core — the complete insulated, triple-glazed, weather-tight building, factory-finished inside and out. You arrange your own floor finish and electrics, in your own time.
- Signature ★ — everything in Core, plus a premium oak-effect luxury vinyl floor and a complete concealed electrical first fix (consumer unit installed; wiring prepared for lighting, sockets and heating). Your electrician completes the second fix.
- Executive — fully turnkey: everything in Signature, plus the complete electrical second fix, Daikin heating & cooling, wired networking and safety systems — tested, certified and commissioned before handover.
Heating and cooling (a Daikin heat pump) is included with the Executive package. With Core or Signature you can have climate control quoted and added later — by VeltHaven or your own installer. There’s no separate add-on price list: the package you choose is the price.
The Core building works out at roughly £1,130–£1,350 per square metre, fully installed, at the sensible end of the UK market for a year-round, insulated, triple-glazed building (London bespoke rooms commonly run £2,450/m² and up).
Every room includes insulated 100mm PIR walls and roof, a triple-glazed four-panel sliding glass wall plus windows, gutters and your choice of RAL colour, the structural base, delivery, installation and VAT, and the VeltHaven 10-Year Structural Warranty (2 years full warranty + structural cover to year 10). Does not affect your statutory rights.
You can price any model and package yourself in the garden room configurator — the estimate updates live, with no obligation.
Running costs
A well-insulated, triple-glazed room is cheap to run. With a heat pump, heating a garden office is far more efficient than plug-in electric heaters; day-to-day cost depends on your tariff, how often you use it and how warm you keep it, but the building’s insulation does most of the work.
Do you need planning permission?
Garden rooms usually fall under permitted development when set back from your boundaries and kept under the height limits — but it depends on size, position and use, and differs in conservation areas. Note that a garden room used as self-contained sleeping accommodation can change the planning position, so it’s never marketed as an annexe or bedroom. We assess yours as part of the design. See our planning permission guide and groundwork guide.
Garden room vs the alternatives
Weighing a garden room against converting your garage? We compare cost, space, planning and disruption in Garden Room vs Garage Conversion.
How to budget
- Pick your finish level — shell, move-in ready, or turnkey. It’s the biggest price lever.
- Add the real extras — base, electrics, access. With VeltHaven these are quoted up front from your photos.
- Match size to use — a 20 m² room suits a single use; 25–30 m² gives room for more than one.
- Decide on heating — for true year-round comfort, choose the Executive package (Daikin heating & cooling included), or add climate control later with Core or Signature.
Garden room cost FAQs
Are garden rooms cheaper than an extension?
Usually, yes — and considerably. A single-storey extension commonly runs £2,500–£4,000+ per square metre once fees, building regs and finishing are counted, against roughly £1,200–£2,500/m² for a garden room, with weeks less disruption and no builders in the house. The trade-off: an extension adds attached, plumbed space; a garden room adds separate space.
Can I get a garden room for £10,000?
At that budget you’re buying an uninsulated summerhouse or a bare DIY kit shell, not a year-round room: fine for summer use, but expect cold, condensation and little winter use. A genuinely insulated, glazed, professionally installed room starts realistically around £15,000–£20,000, and quality builds sit above £25,000. (What actually makes a garden room warm?)
What size garden room can I have without planning permission?
Permitted development normally allows outbuildings covering up to 50% of your garden, kept to height limits (2.5m within 2m of a boundary). Most garden rooms fit comfortably — but rules differ in conservation areas and for listed buildings. See our planning guide.
Do garden rooms need foundations?
Every garden room needs a level, load-bearing base — ground screws or a concrete slab, typically £1,500–£5,000 depending on ground and access. It’s the cost headline figures most often leave out; we quote yours from site photos before you commit. See the groundwork guide.
Does a garden room add value to my home?
Honest answer: it adds space you’ll use every week, and buyers do value a well-built, warm room. But we don’t publish invented “adds £X” percentages, because no credible source can promise one for your street. We’ve written the full honest answer here.
The bottom line
“Garden room” covers everything from a £15,000 summerhouse to a £50,000 turnkey office, so compare the installed, all-in total, not the headline. A VeltHaven garden room starts at £26,950 fully installed, around £1,130–£1,350/m², with the base and electrics quoted before you commit.
See the range on the Garden Rooms page, or build and price yours in a few minutes — free, no site visit needed. Your deposit is fully refundable until you pay your balance.
Every VeltHaven building is delivered and installed by a UK-registered company (Companies House 17261887), with the VeltHaven 10-Year Structural Warranty (2 years full warranty + structural cover to year 10). Does not affect your statutory rights.
