What affects the cost of a garden room?

Published 28 September 2026 · Tom Cutts Joinery & Building

Start with the room you need

A quiet office, a hobby studio and a space for occasional summer use can have different requirements. Write down who will use the room, what needs to fit inside it and whether you expect to use it throughout the year. A sketch showing a desk, exercise equipment or seating often says more than an external measurement on its own.

There is no single price that accurately describes every bespoke garden room. Our team prepares a quotation around the agreed project. The points below help you understand what to include in that conversation.

Six things to discuss when setting a budget

1. Size and layout. Discuss the usable space inside, door positions, storage and room for furniture. A larger footprint also changes the amount of foundation, structure, roof and finishing work.
2. The site and its preparation. Share photographs of the proposed position, changes in level, existing structures and the surrounding ground. The support and foundation approach needs to suit the site and design.
3. Access. Narrow gates, steps or a route through the house are useful details to flag early. Explain where deliveries can arrive and how materials can reach the garden.
4. Comfort and finish. Discuss insulation, ventilation, glazing, cladding, internal linings and flooring together. Ask what is included in the quoted specification and what is an option.
5. Power and other services. List the lighting, sockets, internet connection or other services you need. Confirm who supplies, installs and checks specialist work, and whether it sits within the main quotation.
6. The outdoor space. Decking, steps, paths, a pergola or changes to the surrounding garden should be identified separately so that you can see the whole project cost.

Compare the same scope

Two quotations with the same room dimensions may cover different work. Ask for a written description of the materials, preparation, installation and finish. Check whether waste removal, delivery, services, decoration and any applicable VAT are included, excluded or still to be confirmed.

A lower headline figure is difficult to judge until these details line up. It is also useful to separate essential work from optional finishes, so that any changes to the budget are deliberate.

What to send with your enquiry

• Your postcode and photographs of the proposed position and access.
• Approximate dimensions, plus a simple sketch if you have one.
• How you want to use the room and the furniture or equipment it needs to hold.
• Your preferred finish, rough budget and any timing constraints.
• Any drawings, site information or permissions advice you already have.

Ask at the outset which permissions, specialist design or other checks your project needs and who will arrange them. Those questions should be resolved for your particular site before work is agreed.

Plan the room and deck together

If you are considering both, discuss the entrance, seating area and route back to the house as one layout. The room and deck can then be quoted clearly, with the boundaries of each part of the work explained. Browse our garden-room and decking photographs, choose the details you like and send them with your enquiry.