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.
In Northamptonshire, we price a loft conversion against our guide for the East Midlands, £29,000–£62,000 including VAT, then adjust it once we have surveyed your home. We work across Northampton, Corby, Kettering and Wellingborough and the rest of the county or region. Planning and building control requirements follow the rules for England, and we look into your property's position before a written quote is sent.
- Guide price
- £29,000–£62,000 inc VAT
- Time on site
- 6–10 weeks on site
- Planning rules
- England
- Price level
- About 4% below the national guide
- Towns listed
- 7
- Survey
- Free, with a written quote
How much does a loft conversion cost in Northamptonshire?
What will a loft conversion cost in Northamptonshire? Our guide range is £29,000–£62,000 including VAT. That figure is adjusted for the East Midlands, about 4% below the national guide, and is intended for planning a budget. A firm written price for your chosen specification follows a free survey at your home.
| Type of job | What it usually involves | Guide in Northamptonshire |
|---|---|---|
| Rooflight conversion | Rooflights in the existing slope, a new floor, staircase and insulation, where head height already works. | £19,000–£33,500 |
| Dormer conversion | A rear dormer adding headroom and floor space, often with a bedroom and shower room. | £30,500–£58,000 |
| Hip-to-gable or mansard | Larger structural changes to the roof for the maximum usable space. | £48,000–£82,000 |
The main things that change the figure:
- Conversion type: rooflight, dormer, hip-to-gable or mansard
- Steelwork and any strengthening of walls below
- Adding a shower room or en-suite in the roof
- Staircase layout, fire doors and the level of finishes
What do you get?
- 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
- Staircase designed to fit your landing and meet regulations
- Insulation to walls, roof slope and floor
- Plastering, internal doors and building control sign-off
Housing across Northamptonshire
Orange-brown ironstone is the signature material of many Northamptonshire villages, with limestone and Collyweston stone-slate roofs in the north-east. Northampton has Victorian terraces from its shoemaking era, Corby expanded as a post-war steel town, and Wellingborough, Kettering and Daventry have interwar, post-war and recent estates.
Ironstone cottages often need lime repairs and careful repointing. Terraces suit loft conversions and kitchen extensions, while estate homes commonly take garage conversions, porches and driveways.
An inland county with cold winters and clay soils that can shrink in dry spells; ironstone weathers and needs a suitable mortar.
Do you need permission in Northamptonshire?
England, Wales, Scotland and Northern Ireland each handle planning a little differently. Northamptonshire comes under England, covered below, and we raise any questions with the council before your quote is finalised.
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.
How does the job run?
Survey and measure
We begin by looking at the job in person. During the free survey we discuss options, materials and budget for a loft conversion, and photograph or measure anything the quote needs to reflect.
Your fixed price
We turn the survey notes into a written quote. The price is fixed for the specification we agree, and the document sets out materials, scope and payment stages in plain language.
Dates and permissions
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.
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.
What you can expect from us
Questions about a loft conversion in Northamptonshire
How long will a loft conversion take?
On a typical home, allow 6–10 weeks on site. Larger projects, older buildings and extra work found once things are opened up can extend that, while simpler jobs may be shorter. Your quote includes an estimate of time on site, and your point of contact keeps you updated on the programme as the work progresses.
Do you cover Northampton, Corby and Kettering?
Yes. As well as Northamptonshire, we cover Northampton, Corby and Kettering and the rest of Northamptonshire. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
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 £29,000–£62,000. 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.
Is my loft suitable for conversion?
A loft is usually suitable for conversion if there is enough head height, a roof structure that can be adapted and space for a staircase. A common rule of thumb is at least 2.2m from the top of the ceiling joists to the underside of the ridge, though dormers and mansards can create height where it is short. Modern trussed roofs need more structural work. We check all of this at the survey.
Towns in Northamptonshire
We offer a loft conversion in each of the towns below, all within Northamptonshire. Select yours for guide prices, postcodes covered and nearby places.