One question every buyer asks: 'how do I heat it?'. The honest answer for most insulated timber-frame garden rooms is: less than you think. The airtight envelope holds heat so well that even a slim electric panel can keep a 4×3 m room comfortable through a UK winter, running perhaps 3-4 hours a day at peak season.
The main options
- Slim electric panel radiator (600-1200 W): the most common choice — simple, cheap, no plumbing, wall-mounted
- Underfloor heating (electric mat): premium option, invisible, warm feet — worth it in yoga studios and cinema rooms
- Underfloor heating (wet system): connects to your house heating — only makes sense if you're already extending the plumbing
- Air-source heat pump / split A/C: heats AND cools — genuinely lovely, £2-3k premium, worth it for busy day-use rooms
- Wood-burning stove: for a garden bar or luxury pavilion — needs a certified flue, adds real character
Sizing the heater
As a rule of thumb, an insulated timber-frame garden room needs about 80-100 W of heating per m² of floor area (roughly one-third of what an old, uninsulated room would need). A 12 m² office needs about a 1200 W panel; a 20 m² living room needs a 2 kW output.