If you're considering a garden room in Kent, one of the first things you'll want to know is: how much will it cost? The answer depends on several factors — size, specification, and whether you want extras like a bathroom or kitchen. Here's our honest, transparent breakdown of garden room prices in 2026.
Typical Garden Room Prices in 2026
Based on our experience building bespoke garden rooms across Kent, here are the typical price ranges:
| Type | Price Range | Typical Size |
|---|---|---|
| Garden Room (standard) | £25,000 – £30,000 | 3m × 4m to 4m × 5m |
| Garden Room + Bathroom | £30,000 – £40,000 | 4m × 5m to 5m × 6m |
| Self-Contained Annexe | £60,000+ | 6m × 8m+ |
These are our average order values for bespoke builds. Every project is unique, so your final price will depend on your specific requirements, site conditions, and chosen specification.
What's Included in the Price?
Unlike some companies that quote a low headline price and then add extras, our quotations are comprehensive. Here's what's included as standard in every Kent Bespoke garden room:
- • Ground screw foundations — no concrete, minimal disruption
- • Full structural timber frame — engineered for longevity
- • High-performance insulation — walls, floor, and roof (year-round comfort)
- • EPDM rubber roofing membrane — 10-year guarantee
- • External cladding — James Hardie fibre cement as standard
- • Double or triple glazed windows and doors
- • Full electrical installation — sockets, lighting, consumer unit
- • Internal plastering and decoration
- • Composite decking (Cladco) to the entrance area
- • 10-year structural guarantee
What Affects the Price?
Several factors influence the final cost of your garden room:
1. Size
The bigger the garden room, the more materials and labour required. A compact 3m × 3m home office will cost significantly less than a 6m × 8m annexe with multiple rooms.
2. Specification
Upgrades such as Western Red Cedar cladding (instead of James Hardie), triple glazing, underfloor heating, or premium interior finishes will increase the price. We offer these as options so you can choose what matters most to you.
3. Plumbing
Adding a bathroom, shower room, or kitchenette adds cost for plumbing connections, drainage, and fixtures. A bathroom upgrade typically adds £5,000–£10,000 depending on the specification.
4. Site Conditions
Difficult access, sloping ground, or poor soil conditions can affect foundation requirements and therefore cost. We assess all of this during our free site visit.
5. Planning Requirements
If your project requires planning permission (typically annexes), there are additional costs for architectural drawings, structural engineer reports, and the planning application itself. For annexe projects, we include all of this in our quotation.
Garden Room vs Extension: Cost Comparison
A traditional house extension in Kent typically costs £1,500–£2,500 per square metre, plus architect fees, planning costs, and months of disruption. A bespoke garden room delivers comparable usable space at a lower cost, with minimal disruption, and is typically completed in 4–6 weeks rather than 3–6 months.
Finance Options
We offer flexible finance through Phoenix Financial Consultants from 12.9% APR Representative. You can spread the cost over 3–10 years to suit your budget. This means you can enjoy your garden room now and pay over time. Finance is subject to status and affordability checks. Kent Bespoke Garden Rooms acts as an introducer only and is not a financial adviser.
Get a Fixed-Price Quote
We believe in transparent pricing. After your free consultation visit, we provide a detailed, itemised quotation with a fixed price. There are no hidden costs or surprise extras — the price we quote is the price you pay, unless you request changes to the specification.