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.
Homeowners in East Grinstead usually consider a loft conversion for one of a few reasons: something has worn out, the house no longer suits the way they live, or they are getting it ready to sell. We visit, agree a specification and put a fixed price in writing. Most jobs like this take 6–10 weeks on site, and we work across West Sussex, including Horley, Crawley and Crowborough.
- Guide price
- £33,500–£73,000 inc VAT
- Time on site
- 6–10 weeks on site
- Postcodes
- RH19
- Planning rules
- England
- Local area
- West Sussex
- Survey
- Free, with a written quote
How much does a loft conversion cost in East Grinstead?
What should you budget for a loft conversion in East Grinstead? Use the figures below as a starting point. Prices in the South East sit about 12% above the national guide, so the range here is £33,500–£73,000 including VAT. Your fixed price comes in writing once we've surveyed the property, at no charge.
| Type of job | What it usually involves | Guide in East Grinstead |
|---|---|---|
| Rooflight conversion | Rooflights in the existing slope, a new floor, staircase and insulation, where head height already works. | £22,500–£39,000 |
| Dormer conversion | A rear dormer adding headroom and floor space, often with a bedroom and shower room. | £36,000–£67,000 |
| Hip-to-gable or mansard | Larger structural changes to the roof for the maximum usable space. | £56,000–£95,000 |
Expect these to shape the final quote:
- Conversion type: rooflight, dormer, hip-to-gable or mansard
- Floor area, existing head height and roof structure
- Steelwork and any strengthening of walls below
- Adding a shower room or en-suite in the roof
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
- Insulation to walls, roof slope and floor
- Fire doors, mains-linked smoke alarms and a protected escape route
- Electrics, heating and plumbing by qualified trades, with certificates
Local housing and a loft conversion
Chichester has Georgian brick streets, Downland villages use flint and brick, and Horsham stone slabs cover some older roofs. Worthing and Bognor Regis have interwar and post-war bungalows and semis, Crawley was planned as a post-war new town, and Wealden villages to the north feature tile-hanging and timber framing.
Bungalows commonly suit loft conversions and extensions; new-town homes often take window, roofline and cladding renewal. Flint and stone properties need lime repointing, and coastal homes may need external decorating more often.
None of this holds for every street in East Grinstead, which is why we look at your actual house before pricing a loft conversion rather than assuming from its age alone.
Planning and building rules in East Grinstead
Each UK nation sets its own consent rules, and East Grinstead is in England. What follows is a plain summary; we check the specifics for your property with the council before pricing anything.
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.
The four stages
We look at the job
It starts with a survey at the property, free of charge. We check condition, access and services, ask how you want the finished result to look, and answer any questions you have about a loft conversion.
Price and scope agreed
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.
Getting ready
Next comes planning the work itself. We set a start date that suits you, line up the right trades, and make sure any approvals for a loft conversion are in place before the first day on site.
The work itself
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.
How we work
Common questions
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.
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 East Grinstead 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.
Can I put a bathroom in my loft?
A bathroom or shower room can usually be added in a loft conversion if waste pipes can reach the soil stack with enough fall, or a pumped system can be used. Dormers make this easier because they give standing height for a shower. Water pressure, extraction and the position of the boiler also matter. We plan the bathroom layout at the design stage so pipes are hidden in the structure.
How much does a loft conversion cost?
A typical dormer loft conversion on a 3-bed semi costs £33,500–£73,000. 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.
Does the Party Wall Act apply to a loft conversion?
The Party Wall etc. Act 1996 applies in England and Wales only, and loft conversions on terraced and semi-detached houses often fall within it, because steel beams are usually set into the shared wall. You must serve notice on the neighbour before work starts, and they can agree or appoint a surveyor. Scotland and Northern Ireland have no equivalent Act. We tell you during the survey whether notices are likely.
Also covering areas around East Grinstead
Live in East Grinstead? Our coverage takes in the RH19 postcode areas and reaches out to Horley, Crawley and Crowborough, so homes on the outskirts and in the next town along are included.

