It's the question everyone asks first, and the honest answer is: it depends on what you want the room to do. A bespoke garden room is priced around its size, specification and your garden, so two rooms that look similar in photos can cost very different amounts.
Rather than quote a misleading “from” price, this guide explains what actually drives the cost, so you can plan a realistic budget. For context, the budget options on our enquiry form start at under £20,000 and go up to £50,000 and beyond, which reflects the range of projects people come to us with.
Floor area is the biggest single factor. It's not just more materials: larger rooms may need more substantial foundations, and above certain sizes building regulations approval is needed (see our planning permission guide). A simple rectangular room is more efficient to build than one with extra corners, canopies or a separate WC or storage area.
Glass is one of the most expensive parts of any garden room, and one of the most important to how it feels. Large-format panes, sliding or bifold doors, and triple glazing all add cost, but they also make the room brighter, warmer and quieter. We usually recommend putting the budget into glazing where it frames the best view, and keeping it simpler elsewhere.
A room you'll use every day in a North West winter needs proper insulation in the floor, walls and roof, plus heating (and often cooling). It costs more than a basic summer house, but it's the difference between a room you use all year and one you avoid from October to April.
Level, firm, accessible ground keeps costs down. Sloping gardens, soft or sandy soil, tree roots, or the need to remove an old patio or shed all add work. We assess the ground before recommending a foundation type.
Every garden room needs a safe, certified electrical supply, and the distance from your consumer unit affects the cost of the cable run. Data cabling for a reliable connection is usually a modest extra. Plumbing and drainage for a sink, WC or shower add more, especially if the drainage route is long.
Flooring, wall linings, lighting, built-in storage and joinery all vary widely in price. A cinema room with acoustic treatment and a garden salon with a backwash and wipe-clean surfaces have very different fit-out costs from a simple studio.
If materials can be delivered straight to the back garden, the build is simpler. If everything has to be carried through a house or over a wall, as is common with terraced homes, it takes longer and can cost more.
Many garden rooms are permitted development and need no application. If yours needs planning permission, building regulations approval or a Lawful Development Certificate, allow for fees and drawings.
A well-insulated room is inexpensive to heat, but it will add something to your energy bills. If you use the room for a business with clients, it may be assessed for business rates. It's also worth telling your home insurer about the new building.
The quickest way to a realistic figure is a conversation about how you'll use the room, roughly how big it needs to be, and what your garden is like. Share an approximate budget if you're comfortable doing so, and we'll tell you honestly what's achievable. Start your enquiry, or explore garden room ideas first.
Begin your own project →Size, followed by glazing. Larger rooms need more materials and may need building regulations approval, and large-format or triple glazing is one of the most expensive elements.
Often, because a garden room doesn't alter the structure of your house and usually doesn't need planning permission. But it depends on size and specification. Our garden room vs extension guide compares the two.
Yes. Plumbing and drainage add cost, especially where the drainage route to the house is long. Mention it early so it can be priced accurately.
Garden rooms are generally subject to VAT at the standard rate. Your quotation should make clear whether prices include VAT.
