A loft conversion turns unused roof space into a habitable room such as a bedroom, bathroom or office, with a proper staircase, insulation, fire protection and natural light from rooflights or a dormer.
If you live in Finchley and are weighing up a loft conversion, the starting point is a visit to measure up and talk through what you want, which costs nothing. We cover homes across N2, N3, N12 and NW4, and a typical project of this kind in London lands somewhere in the £39,000–£84,000 bracket, including VAT. The exact figure depends on size, access and the finish you choose.
- Guide price
- £39,000–£84,000 inc VAT
- Time on site
- 6–10 weeks on site
- Postcodes
- N2, N3, N12, NW4 and NW7
- Planning rules
- England
- Local area
- Greater London
- Survey
- Free, with a written quote
What should you budget for a loft conversion in Finchley?
Prices for a loft conversion vary from house to house, but in Finchley most projects fall within £39,000–£84,000 including VAT. That reflects costs in London, about 30% above the national guide. Treat the table as a budgeting aid; the written figure follows a survey we carry out for free.
| Type of job | What it usually involves | Guide in Finchley |
|---|---|---|
| Rooflight conversion | Rooflights in the existing slope, a new floor, staircase and insulation, where head height already works. | £26,000–£45,500 |
| Dormer conversion | A rear dormer adding headroom and floor space, often with a bedroom and shower room. | £41,500–£78,000 |
| Hip-to-gable or mansard | Larger structural changes to the roof for the maximum usable space. | £65,000–£110,000 |
What moves the price up or down:
- Conversion type: rooflight, dormer, hip-to-gable or mansard
- Floor area, existing head height and roof structure
- Adding a shower room or en-suite in the roof
- Staircase layout, fire doors and the level of finishes
What’s included?
- Structural calculations and steel beams where needed
- New floor joists strong enough for a habitable room
- Dormer, hip-to-gable or rooflight structure as agreed
- Fire doors, mains-linked smoke alarms and a protected escape route
- Electrics, heating and plumbing by qualified trades, with certificates
- Plastering, internal doors and building control sign-off
Building in Finchley
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.
These patterns matter for a loft conversion: older walls, roofs and floors in Finchley can need different materials or extra preparation compared with newer homes.
Planning and building rules in Finchley
Homes in Finchley come under the regulations for England, summarised below. We don't rely on general rules alone: we confirm the position for your address with the council before a quote goes out.
In England, many loft conversions are permitted development: up to 40 m³ of extra roof space on a terraced house and 50 m³ on a semi-detached or detached house, no dormer on the front roof slope facing a road, nothing higher than the existing roof, and similar-looking materials. Conservation areas, listed buildings and flats need planning permission.
Building Regulations approval is always needed for a loft conversion: floor strength, a proper staircase, insulation, fire-protected escape route and smoke alarms. The Party Wall etc. Act 1996 usually applies on attached houses.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
From survey to handover
We look at the job
A free survey comes first. It gives us what we need to price a loft conversion properly, including dimensions, existing materials and access for deliveries, and gives you the chance to ask anything you like.
Written quote
You get the price in writing, itemised so you can see where the money goes. As long as the specification stays the same, that is the price you pay for a loft conversion.
Booking the work
Preparation matters as much as the build. We agree access, parking and working hours with you, order materials in good time, and confirm any permissions so the job isn't held up once it starts.
Build and hand over
The work is carried out to the agreed specification, with floors and furniture protected and the site kept tidy. At the end we clean up, walk through the finished job with you and hand over any certificates.
Working with SK Home Improvements
Frequently asked questions
Which postcodes in Finchley do you cover?
We cover N2, N3, N12 and NW4, along with the rest of London. If your postcode is not listed, get in touch anyway: our coverage is UK-wide, and we can usually arrange a survey wherever you live. Enter your postcode in the guide-price tool or contact form and we will confirm.
Where will the new staircase go?
The new staircase usually sits above the existing stairs, rising from the landing so it uses space that is already circulation. Sometimes it needs to come from a small bedroom or box room, which reduces that room's size. Building regulations set rules on headroom, step size and handrails, with some flexibility for lofts. We look at options at the survey and show you how each affects the floor below.
How much does a loft conversion cost?
A typical dormer loft conversion on a 3-bed semi costs £39,000–£84,000. A simple rooflight conversion costs less, while hip-to-gable and mansard conversions cost more because they change the roof structure. As a rough guide, allow around £800–£1,700 per square metre of new floor plus fixed costs for the staircase, steels and fees. Adding a shower room is the most common extra. We confirm a fixed price after surveying your loft.
What fire safety measures does a loft conversion need?
A loft conversion needs a safe way out in a fire, because the new room is high above the ground. This usually means a protected stair route down to an exit, with fire doors onto the stairway, mains-linked smoke alarms on each floor and sometimes an escape window. The exact approach depends on your house layout. Building control checks these measures before signing off the work.
Can you combine a loft conversion with other work?
Yes. Because we manage several trades under one contract, we can plan a loft conversion alongside other work on your Finchley home, such as new windows with rendering, or a kitchen refit with an extension. Combining jobs can reduce repeat set-up such as scaffolding, skips and access, and every element is listed and priced in the same written quote.
Nearby towns
We cover every part of Finchley, including N2, N3, N12 and NW4, and nearby Golders Green, Muswell Hill and Cricklewood. Wherever you are within that patch, the survey is free and the quote comes to you in writing.