How much does a garden room cost in the UK?

Most fully built, insulated garden rooms cost about £1,600 to £2,000 per square metre in Yorkshire, so £19,000 to £24,000 for a 4 × 3 m room. Off-the-shelf small models begin at roughly £10,000. Prices in London and the South East run higher.

What does the square metre price cover?

An insulated floor, walls and roof, double glazed doors and windows, cladding, an electrical supply from the house with lights and sockets, internal lining and fitting. Flooring is usually included; furniture, plumbing and heavy groundwork are not.

Why is a small garden room dearer per square metre?

Doors, the electrics, the survey and the base cost roughly the same for a 6 m² room as a 12 m² one, so they make up a bigger share of the small one. A room twice the size rarely costs twice as much.

Is it cheaper to build a garden room yourself?

The materials for a well-insulated 4 × 3 m room typically run to £8,000 to £12,000, so a capable DIY builder can save a third or more. The electrics must still be done or signed off by a registered electrician, and the time is several weekends at least.

Do garden room prices include VAT?

Most published prices for homeowners include VAT, but not all. A VAT-registered builder adds 20% to a price shown without it, so check which you are looking at before comparing.

How accurate is this calculator?

It is as good as the prices behind it: £1,600 to £2,000 per m² from published Yorkshire price lists, plus typical UK prices for each extra. A level garden with a side gate usually comes out near the middle.

Price calculator

What a garden room costs

Set the width, the depth and the extras. The range updates as you go, and the plan is drawn to scale. Prices are for a room that is built, insulated, double glazed and wired, from Yorkshire builders' published prices, October 2026.

Typical built price

£19,000 to £24,000

12.0 m² floor area

1 m = 30 px. The gap in the outline is the door opening. A typical range, not a quote.

Turn it into a fixed price

01By size

Garden room prices by size

Before extras, rounded to the nearest £500.

Size	Floor area	Typical price
2.5 × 2 m	5 m²	£8,000 to £10,000
3 × 2.5 m	7.5 m²	£12,000 to £15,000
3.5 × 3 m	10.5 m²	£17,000 to £21,000
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
7 × 4 m	28 m²	£45,000 to £56,000

02Extras

What the extras add

Extra	Typical addition
Toilet and basin, or a small shower room	£4,000 to £8,000
Bifold doors in place of sliding doors	£1,500 to £3,000
Air conditioning that heats and cools	£1,500 to £3,000
Bar counter, sink and drinks fridge	£2,000 to £5,000
Slope, steps or awkward access	£1,000 to £3,000

03What moves the price

Six things that push a garden room up or down the range

Size: The biggest factor by far. Each extra square metre adds roughly £1,600 to £2,000, but the first few cost more because the doors, base and electrics are fixed costs.
Glass: A wall of glazing costs more than a wall of insulated timber. Bifolds add £1,500 to £3,000 over sliding doors; a corner of fixed glass adds more again.
Ground and access: A flat lawn with a side gate is the cheap case. A slope, steps, old concrete to break out, or every board carried through a terrace house adds £1,000 to £3,000.
Cable run: The supply comes from your consumer unit. Up to about 20 m is normal; longer runs need a thicker cable and a longer trench.
Water: A sink, toilet or shower means a cold feed and a waste run back to the house drains, and often a small pump if the room sits lower than the drain.
Cladding and roof: Larch and composite boards are the usual choice; cedar, charred timber or a sedum roof cost more and look the part on an architect-designed room.

Planning permission is not usually a cost, because most rooms are permitted development, but an application in a conservation area or for a guest room adds the council fee and drawings. See planning permission in Leeds.

Where these figures come from

Typical prices from published Yorkshire garden room price lists we reviewed in October 2026: £1,600 to £2,000 per m² for an insulated, wired room, with small standard models from about £10,000. Extras are typical UK prices from published price lists reviewed in the same month. There are no reliable figures for Leeds alone, so these are regional prices. Treat the result as a budget, not a quote.

Garden room cost questions

How much does a garden room cost in the UK?: Most fully built, insulated garden rooms cost about £1,600 to £2,000 per square metre in Yorkshire, so £19,000 to £24,000 for a 4 × 3 m room. Off-the-shelf small models begin at roughly £10,000. Prices in London and the South East run higher.
What does the square metre price cover?: An insulated floor, walls and roof, double glazed doors and windows, cladding, an electrical supply from the house with lights and sockets, internal lining and fitting. Flooring is usually included; furniture, plumbing and heavy groundwork are not.
Why is a small garden room dearer per square metre?: Doors, the electrics, the survey and the base cost roughly the same for a 6 m² room as a 12 m² one, so they make up a bigger share of the small one. A room twice the size rarely costs twice as much.
Is it cheaper to build a garden room yourself?: The materials for a well-insulated 4 × 3 m room typically run to £8,000 to £12,000, so a capable DIY builder can save a third or more. The electrics must still be done or signed off by a registered electrician, and the time is several weekends at least.
Do garden room prices include VAT?: Most published prices for homeowners include VAT, but not all. A VAT-registered builder adds 20% to a price shown without it, so check which you are looking at before comparing.
How accurate is this calculator?: It is as good as the prices behind it: £1,600 to £2,000 per m² from published Yorkshire price lists, plus typical UK prices for each extra. A level garden with a side gate usually comes out near the middle.

Get a fixed price

A garden room builder visits, measures the spot and prices your exact room in writing. Start with a postcode.

This is a free introduction service, not a building firm. We find a garden room builder who covers your postcode and tell you who they are before anyone contacts you.

Where is the garden?

Postcode