Garden room prices · 2026
How Much Does a Garden Room Cost?
LouMil garden rooms start from £9,000 inc. VAT. The base price buys the building — prefabricated structure, cladding, EPDM roof, French doors, two full-height windows, delivery and installation. What you add to it is your decision, and every option is priced in the open.
The figures on this page are generated by the same pricing engine as our calculator, so they are current rather than a brochure from last year.
4m x 3m Composite Garden Room – Stafford — a real installed project
Worked examples
Garden room prices at four real sizes
Three specifications for each size: the base building, the base plus insulation & plastering, and a ready-to-use room with insulation & plastering, laminate flooring and the electrical package. All figures include VAT, delivery and installation.
| Size | Base specification | Insulated & plastered | Insulated, floored & wired |
|---|---|---|---|
| 12ft × 10ft11.1 m² · Compact office or studio | £8,764£790/m² | £10,643£959/m² | £12,765£1,150/m² |
| 16ft × 13ft19.3 m² · Family office, snug or gym | £10,121£524/m² | £12,812£664/m² | £15,215£788/m² |
| 20ft × 13ft24.2 m² · Gym, bar or split-use room | £10,976£454/m² | £14,140£584/m² | £16,709£690/m² |
| 26ft × 13ft31.4 m² · Large games room or two-zone space | £12,156£387/m² | £16,028£510/m² | £18,845£600/m² |
Examples use timber cladding, standard French doors and the standard base assumption. Door upgrades, composite cladding, extra windows, ground screws and decorating are added on top when selected. Prices are calculated live and can change; the calculator is always the definitive figure.
What the price includes
Base specification vs the options you can add
We do not advertise an all-inclusive price. The base specification is a complete, weather-tight building; the options are how you make it a finished room.
Included in every garden room
Prefabricated timber structure
Wall, floor and roof panels made to your dimensions in our West Midlands workshop and assembled on site.
External cladding
Timber cladding as standard, with composite available as an upgrade.
EPDM rubber roof
A single-piece rubber membrane roof, covered by the 10-year structural & roof guarantee.
French doors
A set of French doors as standard, with bifold or sliding door upgrades available.
Two full-height windows
Two full-height windows in the base specification; extra windows can be added.
Delivery and installation
Delivered and installed by our own team — no subcontracted install crews.
Option prices
Calculated at 16ft × 13ft. Per-m² options cost more on larger rooms and less on smaller ones.
- +£2,691
Insulation & plastering package
Insulated walls and ceiling, foil-wrapped floor and a plastered internal finish — priced per m², so it scales with the room.
- +£663
Laminate flooring
Fitted floor finish, priced on floor area.
- +£1,740
Electrical package
Certified electrics with spotlights, double sockets, a wall-mounted heater and outdoor lights.
- +£1,800
Bifold door upgrade
Replaces the standard French doors.
- +£1,320
Sliding door upgrade
Replaces the standard French doors.
- +£1,267
Composite cladding
Low-maintenance composite in place of timber cladding, priced on wall area.
- +£1,242
Ground screw base
An alternative to a concrete slab where ground conditions or access suit it.
- +£1,063
Decorating
Optional painting of the plastered interior, billed separately once the plaster has dried. Requires the insulation & plastering package.
What moves the number
Six things that decide what your garden room costs
Size
The biggest single factor. Sizes from 12ft × 10ft up to 40ft × 20ft, in one-foot increments. Larger rooms cost more in total but usually less per square metre, because the doors, windows and installation are spread over more floor area.
Insulation & plastering
Priced per square metre of room, so it scales with size. It is the option that most changes how the room feels and what you can use it for.
Electrics & heating
A fixed-price electrical package with spotlights, sockets, a wall-mounted heater and outdoor lighting, certified on completion. Extra sockets and lights can be added.
Doors and windows
French doors and two full-height windows are standard. Bifold or sliding door upgrades and additional windows are itemised separately.
Cladding
Timber is standard. Composite or slatted composite cladding costs more up front and needs far less maintenance over the life of the room.
Base and access
The price assumes a level, suitable base — concrete, paving or compacted hardcore. If you do not have one, select the ground screw option. Access is confirmed at survey so there are no surprises on installation day.
Installation time is different from lead time: your slot from order to installation is confirmed with you at the point of booking. The structure and EPDM roof carry our 10-year guarantee. Doors, windows, electrical fittings and other components are covered by their manufacturers' warranties.
Why we can price online
Prefabricated, so the price is known before we arrive
Because the panels are made in our workshop to your dimensions, we know the material and labour for your room before it leaves the building. That is why the calculator can commit to a figure, and why installation is typically 3–5 days on site rather than weeks of framing in your garden.
Site-built rooms are usually priced after a sales visit and adjusted as the job goes on. Ours is priced by you, in the open, before anyone calls.
Compare like for like
- Is VAT included? Ours always is.
- Is delivery and installation included? Ours is, nationwide.
- Is insulation included or an option? Ours is a clearly priced option, not a hidden assumption.
- Who installs it? Our own team, not a subcontracted crew.
- What is guaranteed? Structure and roof for 10 years.
Priced this way, built this way
Prefabricated garden rooms we have installed
Real projects specified through the same size-and-options approach.
Pricing questions
Garden room cost FAQs
How much does a garden room cost in the UK?
A LouMil garden room starts from £9,000 inc. VAT for the base specification, which includes the prefabricated structure, external cladding, EPDM roof, French doors, two full-height windows, delivery and installation. A fully specified room with insulation and plastering, flooring and the electrical package costs more, and the exact figure depends on size. The worked examples on this page are calculated live from our current pricing.
Is VAT included in your garden room prices?
Yes. Every price in the calculator and on this page includes VAT, delivery and installation by our own team. The only item billed separately is decorating, which happens once the plaster has dried after installation.
What is not included in the price?
The price assumes you have a level, suitable base and that we can get the panels to the position in your garden. Ground screws are available as an option if you do not have a base. Connection of the electrical package to your house supply is discussed at survey, and planning applications, where required, are handled separately.
How much does an insulated garden room cost?
Insulation and plastering is priced per square metre, so the uplift depends on the room size. The examples above show the base price and the insulated price side by side for four common sizes. Our insulated garden rooms page explains what the package includes.
Do you offer finance?
Not at present. Payment is staged across the project and the schedule is set out in your proposal before you commit.
Are these prices fixed?
The price you build in the calculator is the price in your proposal for the specification shown. If you change the specification, the price changes with it, and you will always see the new figure before approving anything.
Useful next steps
Where to go from here
See your price
Choose your size and specification in the calculator and see the full price including VAT.
Read moreInsulated garden rooms
How the insulation & plastering package works and when it is worth selecting.
Read moreCost per square metre
How garden room pricing scales with size and specification.
Read moreGarden rooms
The LouMil prefabricated bespoke garden room system explained.
Read more