Garden rooms: costs, planning and powering one with solar

An insulated garden room for a home office typically costs from around £15,000 to £40,000 installed, depending on size and finish. Most fall under permitted development if they are single-storey, under 2.5m tall within 2m of a boundary, and not used as a bedroom. Check with your council if you're in a conservation area or listed building.

A small solar array on the roof can cover lighting, a laptop and a heater on mild days, and a battery can store daytime power for the evening.