Gable Roofed
School Classroom
Golf Room
Snooker Room
Home Office
Home Gym
Garden Annex
Garden Studio
Cinema Room
Cocktail Bar
Indoor Pool
Beautician's Studio
Café Area
Rated 5.0 from 60+ Google reviews
Your perfect garden room, annexe or studio
Insulated, low-maintenance composite garden rooms and annexes, built to last and enjoyed all year round.
Who We Are
Two premium ranges, one composite promise
Composite Garden Buildings design, manufacture and install insulated garden rooms and luxury annexes across the UK.
Built from high-performance composite that looks and feels just like timber, without the rot, painting or staining. Every building is bespoke. Whether it's an office, bar or annexe, our set sizes are designed to make the most of the material, but yours can be tailored to suit. Need it smaller, or want extra internal walls, doors or electrical sockets? No problem. Build it your way with our online designer.
Garden Rooms
Garden Rooms
From £12,096 inc. VAT & installationA versatile space designed for any use and any size - offices, studios, gyms and retreats.
Annexes
Granny Annexes
A fully customisable, self-contained habitable space - designed to be lived in all year round.
Real Annexe Pricing
Wondering what an annexe really costs?
No vague "from" prices or guesswork. Browse genuine, fully-costed annexe and glamping pod projects, with the real figures behind every build, so you can plan your own with total confidence.
How Would You Use Yours?
Your space, your way.
Why Composite
The smart alternative to timber
Every building shares the same high-performance composite construction. Here's what that means for you.
Authentic Timber Look
Embossed woodgrain composite that looks and feels just like real timber.
Zero Maintenance
No rotting, painting or staining - ever. Just wipe clean and enjoy.
Highly Insulated
Warm in winter, cool in summer and comfortable to use all year round.
Built to Last
Robust composite construction with secure, high-quality locking.
Fully Weatherproof
Engineered and tested for the British climate, rain or shine.
Quick to Install
Most builds are completed in just 3 to 5 days from start to finish.
Choice of Colour
Single or dual rich woodgrain tones to complement your home.
High Security
Secure, high-quality locking on all windows and doors.
How It Works
From first call to finished space
A simple, guided process. Most projects are completed in a matter of days.
1
Enquire & Quote
Call, request a callback or use the online designer for a fast, no-obligation quote.
2
Design & Customise
Choose your model, size, colours and upgrades to make the space yours.
3
Base & Install
We prepare the base and build on site, usually within 3 to 5 days.
4
Enjoy Year-Round
Move in and enjoy a low-maintenance space backed by our aftercare.
Work From Home
A professional office, just steps from your back door
With lower overheads and no daily commute, more people than ever are choosing to work from home. A customisable composite garden office gives you a dedicated, professional space to focus, and a clean break between work and home life.
- Fully insulated and comfortable to work in all year round
- A quiet, separate space away from household distractions
- Power, lighting and data points built into your layout
- Reclaim your commute and your work-life balance
Start Today
Ready to get started?
Get a free, no-obligation quote, or design your dream building online in minutes.
Our Work
See our work
A few of the spaces we've designed, built and handed over, every one unique to its owner.
Areas We Cover
Designed and installed across England
Based at our Show Village in Northamptonshire, our teams design, deliver and install garden rooms and annexes nationwide.
Not sure if we cover your area? Get in touch and we'll let you know.
Northamptonshire
Cambridge
Peterborough
Leicester
Nottingham
Milton Keynes
Bedfordshire
Coventry
Birmingham
Oxfordshire
London
Bristol
Hassle-Free Living
No Rotting. No Painting. No Staining.
Finish your project with matching composite decking and spend less time on upkeep, more time enjoying your space. The authentic woodgrain of timber, engineered to last.
See It For Yourself
Watch our customers' dream spaces
Home Comforts Garden Annex
Garden Office with Storage
Holiday Retreat for Mum
Rated 5.0 on Google
Why our customers love us
“The jewel in the crown of our garden.”
“From start to finish they’ve been faultless.”
“Zero maintenance and looks premium. It does not disappoint.”
“Outstanding quality, finished in a day and a half.”
I did a lot of research on who to go with to build our garden room and I couldn't be happier. From start to finish they've been faultless. Always on time and a pleasure to deal with.
Charlie WillisonThe team jumped through hoops to give me exactly what I wanted. The install team were exceptionally hard working, punctual and polite. The jewel in the crown of our garden.
Stephen WellerExcellent premium quality product. I wanted a composite product that requires zero ongoing maintenance and looks premium - my garden room does not disappoint!
R. MackettOutstanding service and quality build. The whole thing was finished in a day and a half. The build team were polite, tidy and a pleasure to deal with.
Ann Woolfe
Spread the Cost
Check your eligibility
Garden room finance made easy
Make your garden room or annexe more affordable and pay monthly with flexible finance options.
1Apply online in minutes
2Get a quick decision
3Spread the cost monthly
Finance available subject to status. Composite Garden Building Ltd is a credit broker, not a lender.
Take One Home
Get the full brochure
Browse the entire range, configurations, options and upgrades, free to download and keep.
Download the brochure
Visit Us
See the quality for yourself at our Show Village
Walk around full-size garden rooms and annexes at our Show Village in Islip, Northamptonshire. It's the best way to experience the build quality before you buy.
- Full-size show buildings to explore inside and out
- Chat through your project with the team, no pressure
- Open by appointment, so call ahead to arrange your visit
Let's Build Something
Your dream garden space starts here
Get a free, no-obligation quote today, or visit our Show Village in Islip, Northamptonshire to see the quality for yourself.
COMPOSITE GARDEN BUILDING LIMITED is an introducer appointed representative of Ideal Sales Solutions Ltd T/A Ideal4Finance. Ideal Sales Solutions is a credit broker and not a lender (FRN 703401). Finance available subject to status. The rate offered is always provisional and will depend upon your personal circumstances, the loan amount and term.