Garden Rooms, Offices & Studios
What does a garden room really cost, and why do quotes vary so much?
Garden room quotes are hard to compare because two builders can use the same words and mean very different buildings. One price includes a concrete base, a warm roof, plastered walls and certified power. The other is a shell dropped on your existing patio. Below are honest UK ranges and, more usefully, the specific things that push a number up.
Typical UK price ranges
These are broad market ranges for a supplied and fitted insulated garden room in the South East, including a suitable base and power, at the time of writing. They are a sanity check for budgeting, not a quote, because ground conditions and access change the groundworks element significantly.
| Footprint | Simple insulated spec | Higher specification |
|---|---|---|
| Around 3m x 2.5m | £12,000 to £18,000 | £18,000 to £25,000 |
| Around 4m x 3m | £18,000 to £26,000 | £26,000 to £38,000 |
| Around 5m x 4m | £26,000 to £38,000 | £38,000 to £55,000 |
| Room plus shower and WC | Add £6,000 to £12,000 | Depends on drainage runs |
The five things that move the price most
If you want to understand a quote quickly, look at these before you look at the cladding.
- Groundworks: sloping plots, poor access and clay soil all add labour and material before anything is built
- Insulation depth and continuity: a genuinely warm building costs more in materials and detailing than a lightly insulated one
- Glazing: large aluminium sliders are a big line item next to a standard door and window set
- Internal finish: taped and jointed boards cost less than a plastered and decorated interior
- Services: distance from the consumer unit, trench length, and whether you want water and waste
Where people accidentally spend more later
The cheapest quote often becomes the most expensive building. Retro fitting insulation, replacing a base that has settled, or bringing uncertified electrics up to standard costs more than doing it once.
The other common one is heating. A thin building needs a bigger heater, which then runs for longer, every winter, forever. Insulation is a one off cost. Heat loss is a subscription.
How to compare two quotes fairly
Put them side by side and check they describe the same building. If a line is missing from one quote, it is not free, it is just not there yet.
- Base type, thickness and whether spoil removal is included
- Insulation type and thickness in floor, walls and roof
- Roof covering, falls and how rainwater leaves the building
- Electrical work, certification and whether the trench is included
- Internal finish level: boarded, skimmed, or skimmed and decorated
- Waste removal, and reinstatement of any lawn or path used for access
Getting a real figure
We are based in Tunbridge Wells and quote garden rooms across Kent, Sussex and Surrey after visiting the site, because the ground and the access genuinely change the number. The quote is written, itemised and free.
Want a professional to handle it?
Request your free, no-obligation quote through our enquiry form — it takes under two minutes and goes straight to Elliot.
Request my free quoteYou'll be taken to our secure TradeHQ enquiry form. We reply within 48 hours. Prefer to talk? Call 07850 357962.
Frequently asked questions
Talk it through before you spend anything
Send a few photos of the garden and rough dimensions and we will tell you honestly which range you are in before anyone visits. The site visit and written quote cost nothing.
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