Loft Conversion Cost (2026 UK Guide)
A loft conversion typically costs £25,000 to £75,000 in 2026 depending on the type, with a simple Velux conversion starting around £25,000 and a full mansard reaching £75,000+. As well as adding usable space, a well-built loft conversion is one of the highest-return home improvements, often adding more to your home’s value than it costs. The figures here are typical 2026 UK ranges to help you budget; for a firm price, compare quotes from a few loft conversion specialists and builders.
We’re an independent directory, not a builder or design-and-build firm. We don’t sell loft conversions — we compare your options and route you to multiple vetted specialists so you can choose the right one for your home and budget.
Loft conversion cost at a glance (2026)
Here’s a price-at-a-glance summary of loft conversion costs by type in the UK as of 2026. Prices include design, build and building control sign-off, but exclude furnishing.
| Conversion type | Typical cost | Cost per m2 | Timescale | Adds a bedroom? |
|---|---|---|---|---|
| Velux / rooflight | £25,000 – £40,000 | £1,250 – £1,800 | 4 – 6 weeks | Often yes |
| Dormer (most common) | £35,000 – £60,000 | £1,500 – £2,200 | 6 – 8 weeks | Yes |
| Hip-to-gable | £45,000 – £65,000 | £1,800 – £2,400 | 7 – 9 weeks | Yes |
| Mansard (most expensive) | £55,000 – £75,000+ | £2,000 – £2,800 | 8 – 12 weeks | Yes (often + en-suite) |
Typical 2026 UK ranges including design, build and building control. Prices are guide figures, not guaranteed quotes — get a free quote for your loft.
These ranges assume a standard build with a good-quality finish. Adding an en-suite, upgrading the staircase, a complex roof structure or a high-end finish all push the price up — see what affects the price below. To turn these figures into a firm number, compare quotes from loft conversion specialists near you.
Loft conversion cost by type
The biggest factor in the price of a loft conversion is the type, because each involves a different amount of structural work to the roof.
Velux / rooflight loft conversion cost (the cheapest)
A Velux (or rooflight) conversion keeps the existing roof shape and simply adds windows set into the roof slope, plus insulation, flooring, a staircase and finishing. It’s the simplest and cheapest option, but it only works if you already have enough head height.
- Typical cost: £25,000 to £40,000
- Best for: lofts that already have generous head height
- Timescale: around 4 to 6 weeks
Because there’s no change to the roofline, a Velux conversion almost always falls under permitted development — no planning application needed in most cases.
Dormer loft conversion cost (the most common)
A dormer extends out from the roof slope to create a box of full-height space, dramatically increasing usable floor area and headroom. It’s the most popular type in the UK because it balances cost, space and planning friendliness.
- Typical cost: £35,000 to £60,000
- Best for: terraced and semi-detached homes needing more headroom
- Timescale: around 6 to 8 weeks
As a citable headline: the average dormer loft conversion costs around £35,000 to £60,000 in 2026, depending on size, the number of dormers and the finish.
Hip-to-gable loft conversion cost
A hip-to-gable conversion is for homes with a hipped (sloping) side roof — common on semi-detached and detached houses. The sloping side is built up vertically to a gable end, creating much more internal volume, and it’s often combined with a rear dormer.
- Typical cost: £45,000 to £65,000
- Best for: semi-detached and detached homes with a hipped roof
- Timescale: around 7 to 9 weeks
Because it changes the roof shape, a hip-to-gable conversion is more likely to need planning permission, especially on the side elevation.
Mansard loft conversion cost (the most expensive)
A mansard rebuilds one or both slopes of the roof into a near-vertical wall with a shallow top, maximising space across the whole footprint. It looks the most seamless and adds the most room, but it’s the biggest structural job.
- Typical cost: £55,000 to £75,000+
- Best for: maximising space, period and terraced homes, conservation areas
- Timescale: around 8 to 12 weeks
Mansards almost always need planning permission and, in conservation areas, are often the only style approved because they suit the streetscape.
Loft conversion cost by size and added bedrooms
Loft conversions are usually priced by the project, but it helps to think in cost per m2 — typically £1,250 to £2,800/m2 depending on type and finish. The other big variable is what you put in the new space.
| Project | Typical cost |
|---|---|
| Single loft room (no en-suite) | £25,000 – £45,000 |
| Loft bedroom with en-suite | £40,000 – £65,000 |
| Large dormer/mansard suite (bedroom + en-suite + dressing area) | £55,000 – £75,000+ |
Typical 2026 UK ranges. Get a quote for your loft’s exact size and layout.
Adding an en-suite is the single biggest optional cost, because it means running new plumbing and waste up into the loft. It’s also one of the most valuable additions for resale, so it’s often worth it.
What’s included in a loft conversion quote
A proper loft conversion quote should be a complete, build-ready package. Typically it includes:
- Structural steels (RSJs) and any beam work to support the new floor and roof
- A staircase up to the new room (and sometimes alterations to the floor below)
- Insulation to meet current building regulations
- Dormer construction or roof alterations (for dormer, hip-to-gable and mansard types)
- Windows and rooflights
- Electrics — lighting, sockets, smoke alarms
- Plumbing if you’re adding an en-suite
- Plastering and finishing
- Building control sign-off — the certificate confirming the work meets regulations
Always check whether furnishing, fitted wardrobes, flooring upgrades and decoration are included or extra. A clear quote that lists exactly what’s covered is the only reliable figure — compare quotes from loft specialists and check each one itemises the package.
What affects loft conversion price
Two homes on the same street can get very different quotes. The main cost drivers are:
- Conversion type — as above, Velux is cheapest and mansard most expensive.
- Property type — terraced, semi-detached and detached homes each present different roof structures and access.
- Head height — if you don’t have enough headroom, the roof may need raising or a more involved conversion, adding cost.
- Party wall agreements — terraced and semi-detached conversions usually need a Party Wall Agreement with neighbours, which can mean surveyor fees.
- En-suite or bathroom — adding plumbing up into the loft increases both cost and value.
- Planning vs permitted development — work needing planning permission carries application fees and time; conservation areas add restrictions.
- Finish level — standard, mid-range or high-end fittings, flooring and joinery make a big difference.
- Labour rates — the single biggest regional variable, which is why prices differ across the UK (see below).
Loft conversion cost by region (2026)
Where you live affects what you pay, mainly through local labour rates. London and the South East are the clear premium outlier, running roughly 20 to 40% above the national average, while the Midlands, the North, Wales and Scotland are materially cheaper. Our own demand data backs this up: building work in London commands far higher advertiser costs than in Liverpool, Leeds, Manchester, York or Nottingham, reflecting higher labour rates and overheads in the capital.
| City / region | Cost vs national average | Notes |
|---|---|---|
| London | Highest (20 – 40% above) | Premium labour and overheads |
| Bristol & South West | Above average | Tracks the South East |
| Birmingham | Around average | Mid-range Midlands |
| Manchester | Around / below average | Mid-range North West |
| Leeds | Below average | Lower labour rates |
| Liverpool | Below average | Among the lower-cost cities |
| York | Below average | Lower labour rates |
| Nottingham | Below average | Lower labour rates |
| Glasgow | Below average | Lower labour rates |
| Edinburgh | Around / below average | Slightly higher than Glasgow |
| Cardiff | Below average | Lower labour rates |
Directional 2026 guide based on regional labour costs, not fixed quotes. Get free local quotes for your area.
The practical takeaway: if you’re in London or the South East, comparing three or more quotes matters even more, because the spread between builders is wider. Wherever you are, comparing local loft conversion specialists is the surest way to find a fair price.
Does a loft conversion add value?
Yes — a loft conversion is consistently one of the highest-return home improvements in the UK. A well-built conversion that adds a bedroom (ideally with an en-suite) can add roughly 15 to 20% to a property’s value, and in higher-value areas the uplift can exceed the build cost.
Two things drive the return: adding a bedroom moves the home into a higher band for buyers, and a loft conversion does it without losing garden space. As with any improvement, check your local ceiling price — the most a home on your street realistically sells for — before committing, so you don’t over-invest beyond what the area supports.
This is exactly the calculation many homeowners weigh against an extension. If you’re deciding between the two, compare with house extension costs to see which adds more value for your budget and property.
Loft vs extension: which adds more value?
Both add space, but they suit different homes:
- A loft conversion uses existing roof space, doesn’t eat into the garden, and is often the better value per square metre for adding a bedroom.
- A house extension adds ground- or multi-storey space, suits enlarging living areas and kitchens, and can add more total floor area — but usually costs more and may need more land.
If you mainly need an extra bedroom, the loft often wins on cost and ROI. If you want a bigger kitchen or living space, an extension is usually the answer. Many homeowners get quotes for both and compare. Compare house extension costs here.
How to save on a loft conversion
A few sensible moves can bring your loft conversion cost down without compromising quality:
- Stay within permitted development — designing to permitted-development rules (where possible) avoids planning fees and delays.
- Choose a fixed-price design-and-build — an all-in fixed price (design, structure, build, building control) makes budgeting easier and limits surprise extras.
- Keep the layout simple — a straightforward dormer over a complex mansard, or one en-suite rather than two, saves significantly.
- Compare 3 or more quotes — prices for the same project vary widely between builders, so always get at least three.
- Get the spec in writing — a clear, itemised quote lets you compare like with like and avoid mid-build cost creep.
We don’t sell loft conversions, so we have no reason to steer you toward the most expensive option — our job is to help you compare and choose.
How to get free loft conversion quotes
The figures in this guide are typical 2026 ranges to help you plan. For a price you can rely on, you need quotes for your specific loft from vetted specialists.
Here’s how to compare well:
- Get at least three quotes so you can spot a fair price and an outlier.
- Make sure quotes are like-for-like — same conversion type, same finish, same inclusions (en-suite, staircase, building control).
- Check insurance and accreditations — use builders who are insured and reviewed, and ask about relevant trade memberships.
- Confirm what’s included — structure, staircase, insulation, windows, electrics, plumbing, plastering and sign-off should all be itemised.
- Ask about Party Wall Agreements — find out whether one is needed and who arranges it.
Through Trusted Tradesmen Quotes, you can request free, no-obligation quotes from loft conversion specialists and builders near you in minutes. Because we’re independent, we connect you with multiple specialists — not a single design-and-build company.
You can also find a trusted tradesman for any other job, or browse our other home improvement cost guides — including house extension cost and kitchen renovation cost.
Get free quotes from loft conversion specialists near you and compare your loft conversion cost today.
Frequently asked questions
How much does a loft conversion cost in 2026?
A loft conversion typically costs £25,000 to £75,000 in 2026. A simple Velux/rooflight conversion starts around £25,000, a dormer (the most popular type) runs £35,000 to £60,000, a hip-to-gable £45,000 to £65,000, and a mansard £55,000 to £75,000+. The best way to get an accurate figure is to compare a few local quotes.
How much is a dormer loft conversion?
A dormer loft conversion — the most popular type in the UK — usually costs £35,000 to £60,000 in 2026, depending on the size, the number of dormers and the finish level. Adding an en-suite increases the cost but also adds value.
Does a loft conversion add value to a house?
Yes — a well-built loft conversion that adds a bedroom can add roughly 15 to 20% to a property’s value, often more than it costs, especially with an en-suite. Check your local ceiling price first so you don’t over-invest beyond what your area supports.
Do I need planning permission for a loft conversion?
Many loft conversions fall under permitted development, particularly Velux/rooflight conversions and rear dormers within size limits. However, dormers on the front elevation, mansards, and any conversion on a property in a conservation area usually need planning permission. Always check the current rules with your local council.
How long does a loft conversion take?
Most loft conversions take 6 to 10 weeks on site, with Velux/rooflight conversions the fastest (around 4 to 6 weeks) and mansards the longest (8 to 12 weeks). Design, planning and building control approvals happen before work starts and add to the overall timeline.