Build your own garden room. Save £15,000+.
Step-by-step DIY build guides for UK garden rooms. Covers planning permission, foundations, framing, insulation, cladding, and finishing — with realistic cost breakdowns and material lists.
Typical 4×3m garden room
DIY cost: ~£6,500 • Professional: ~£18,000
Everything you need to build
From first planning question to final coat of paint — we cover every stage of a DIY garden room build.
Accurate cost calculator
Get a realistic DIY materials cost for your chosen size and spec — broken down by category so you know exactly where the money goes.
Try the calculator →Size-by-size build guides
Detailed guides for the UK's most popular sizes — 4×3, 5×3, 6×3, and 6×4. Covers foundations, framing, insulation, cladding, and finishing.
Browse guides →Planning permission clarity
Plain-English explanation of UK Permitted Development rules for garden rooms, including the key size thresholds and common gotchas.
Read the guide →Complete build pack
Everything in one place — full plans, cutting lists, material quantities, tool checklist, and a weekend-by-weekend build timeline for £49.
Get the build pack →Why trust this guide?
GardenRoomDIY is built by people who have actually built garden rooms in the UK. Every cost figure, every material quantity, and every planning note comes from real builds — not guesswork.
- Based on real UK build costs (updated 2024)
- Covers all major UK sizes from 3×2.5m to 8×4m
- Plain-English planning permission guidance
- No fluff — just what you need to build
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Size guides
Pick your size and get the full build breakdown.
4×3m Garden Room
The Perfect Home Office
The 4×3m garden room is the UK's most popular size — big enough for a comfortable home office or hobby room, small enough to fit most gardens without planning permission.
5×3m Garden Room
Versatile Space for Work or Play
The 5×3m offers an extra metre of width over the 4×3m, making it ideal for dual-purpose rooms — a home office with a meeting area, or a hobby room with proper storage.
6×3m Garden Room
Serious Space for Serious Builds
The 6×3m is the go-to size for those who want a proper room at the bottom of their garden. Long and lean, it suits workshops, studios, and dual-function spaces.
6×4m Garden Room
Premium Garden Room for Ambitious Projects
At 24m², the 6×4m is a proper room that rivals many spare bedrooms. This size opens up possibilities for commercial use, large studios, or multi-function spaces.
Ready to build your garden room?
Get the complete DIY build pack — full plans, materials list, and step-by-step guides for £49.