A garage conversion turns an integral or attached garage into a warm, habitable room by insulating the floor, walls and ceiling, replacing the garage door with a wall and window, and adding heating, lighting and finishes.
Planning a garage conversion for a home in Blackheath means making a handful of decisions about materials, layout, finish and timing. We help you work through them at a free survey, then confirm in writing what it will cost for the options you pick. Most projects of this type need 2–6 weeks on site, and we cover every SE3, SE4, SE7 and SE10 address as well as the rest of London.
- Guide price
- £15,500–£36,500 inc VAT
- Time on site
- 2–6 weeks on site
- Postcodes
- SE3, SE4, SE7, SE10 and SE12
- Planning rules
- England
- Local area
- Greater London
- Survey
- Free, with a written quote
Garage conversions prices in Blackheath
Use the table to gauge the cost of a garage conversion in Blackheath before we visit. Figures include VAT and are scaled for London, coming out about 30% above the national guide, which gives £15,500–£36,500 overall. After a free survey, you receive a fixed written price.
| Type of job | What it usually involves | Guide in Blackheath |
|---|---|---|
| Integral single garage | A garage within the house footprint, with sound walls and a roof already in place. | £13,000–£23,500 |
| Attached single garage | A garage beside the house that may need roof, wall or floor upgrades. | £18,000–£32,500 |
| Double or detached garage | A larger or separate building, often with a shower room or kitchenette. | £28,500–£58,000 |
The main things that change the figure:
- Garage type: integral, attached or detached
- Condition of the floor, walls, roof and foundations
- Heating method and ventilation for the new room
- Window and door choices and the level of finishes
What do you get?
- Infilling the garage door opening with insulated wall and new window
- Damp-proof membrane, insulated floor and screed or raised timber floor
- Insulated walls and ceiling built to building regulations
- New internal door or opening into the house
- Electrics, heating and ventilation by qualified trades, with certificates
- Plastering, skirting and decoration-ready finish
What are homes like around Blackheath?
London's housing is dominated by Victorian and Edwardian terraces, often in yellow London stock brick, with Georgian terraces in central districts and mansion blocks across many inner areas. Outer boroughs have large belts of interwar semis, and there are extensive post-war council estates. Many houses have been split into flats, and conservation areas are widespread.
London Clay shrinks and swells with the seasons, and street trees close to houses can contribute to movement, which affects foundation design.
That variety is why a guide price for a garage conversion in Blackheath is only a starting point; the survey shows what your particular property needs.
Do you need permission in Blackheath?
As Blackheath is in England, read the following with that system of planning and building control in mind. We check what applies to your house with the council before you receive a quote.
In England, converting an attached or integral garage into a room usually needs no planning permission, unless a planning condition on your estate has removed permitted development rights (common on newer houses). Changing the garage door to a wall and window is generally fine.
Building Regulations approval is needed: foundations for the infill wall, a damp-proof course, insulation, ventilation and fire safety.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
How does the job run?
Survey and measure
We arrange a free site survey on a date convenient to you. We measure up, look at the existing structure and access, and discuss your plans for a garage conversion so the price reflects your home.
Your fixed price
We put everything into a written, fixed-price quote: the specification, what's excluded, staged payments and the expected time on site. Take whatever time you need to decide; there's no pressure to commit.
Dates and permissions
With the quote agreed, we book the work in and handle preparation: permissions where needed, building control notifications, material orders and access arrangements for your Blackheath property.
Finish and handover
During the work we protect the areas around it and tidy up at the end of each day. Once complete, we check the finish, remove our materials and hand over paperwork such as building control sign-off where it applies.
Why homeowners choose us
Frequently asked questions
What happens at the survey?
We visit your home at a time that suits you, look at the area involved, take measurements and check access, condition and any services that might be affected. We talk through what you want from a garage conversion, explain the options and answer questions. There is no charge and no obligation; afterwards we send a written quote.
Can I stay at home during the work?
In most cases, yes. Most people can live at home throughout, and we plan the work to keep disruption down by protecting floors, agreeing working hours and keeping access routes clear. Bigger jobs affecting kitchens, bathrooms or heating may mean a short spell with reduced facilities, and we talk this through with you at the survey.
Do I need planning permission for a garage conversion?
Whether a garage conversion needs planning permission depends on the works, your home's location, whether it is listed or in a conservation area, and which UK nation you are in. In England, converting an integral or attached garage is often permitted development where changes are mostly internal, unless a planning condition has removed those rights, which is common on newer estates. We check what applies before quoting.
How long does a garage conversion take?
A straightforward integral garage conversion usually takes two to four weeks on site. Attached garages that need roof or wall upgrades, and conversions with a shower room, typically take four to six weeks. Detached garages turned into annexes can take longer. Before work starts, allow time for drawings and building control approval. We give you a clear programme with your written quote.
Will losing the garage affect parking?
Losing a garage can matter if your street has parking pressure or your property deeds or planning conditions require off-street parking. Many garages are too narrow for modern cars, so in practice the driveway often provides the parking anyway. We check for planning conditions affecting the garage before quoting. If you need extra parking, we can also price a driveway extension.
Also covering areas around Blackheath
Our coverage in Blackheath includes SE3, SE4, SE7 and SE10. We also travel to Greenwich, Catford and Eltham, so neighbouring addresses are looked after on exactly the same terms as those in town.

