Services
Garage, basement and barn conversions
Converting space you already have is often the quickest way to gain a room. We handle the structural, damp-proofing, insulation and approval work that makes a conversion a proper part of the house.
Choose a project
Garage conversionsTurn an integral or attached garage into a room, office or annexe.£18,000–£30,000 for a single integral garageLearn more
Basement conversionsConvert a cellar or dig a new basement for extra living space.£1,900–£3,200 per m² for converting an existing cellarLearn more
Barn conversionsConvert a barn or agricultural building into a home.£1,800–£3,000 per m² of floor areaLearn more
Garden annexesA self-contained annexe for family, guests or a home office.£1,800–£2,800 per m² of floor areaLearn more
| Project | Guide price | Time on site |
|---|---|---|
| Garage conversions | £18,000–£30,000 for a single integral garage | 3 to 6 weeks on site |
| Basement conversions | £1,900–£3,200 per m² for converting an existing cellar | 8 to 16 weeks for a cellar conversion; longer for new excavation |
| Barn conversions | £1,800–£3,000 per m² of floor area | 6 to 12 months on site depending on condition |
| Garden annexes | £1,800–£2,800 per m² of floor area | 10 to 16 weeks on site |
Questions about garage, basement and barn conversions
Do I need planning permission for a garage conversion?
Usually not if the work is internal and the house keeps its permitted development rights. Many newer houses have planning conditions that remove those rights, in which case an application is needed.
Does a basement conversion need planning permission?
Converting an existing cellar without changing the outside usually does not. New excavation, lightwells and changes visible from outside usually do.
Do I need planning permission for a barn conversion?
Yes. A barn conversion needs planning permission or, in England only, prior approval under the agricultural permitted development rules where the building qualifies. Listed barns also need listed building consent.
Does a garden annexe need planning permission?
Usually yes if it is used as living accommodation. Outbuildings under permitted development must be incidental to the house, such as a gym or office, not bedrooms.
Start with a free home visit
Call 0800 088 6248 or get an instant guide price online.