By Emily Rivers
Last updated 5th June 2025

Loft conversion price guide

How much does a loft conversion cost? If you know your attic space is suitable for a loft conversion, you’re probably wondering how much it’s going to set you back. A loft conversion can add thousands to the value of your home and gives you a versatile space to use with your family.

The average cost of a loft conversion is £40,000. It’s likely to take up to 12 weeks. But costs vary depending on the type of roof you have, your location and how big you’d like your conversion to be - so make sure you get a range of quotes from reputable tradespeople to ensure you’re paying a fair price.

Cost to build a loft conversion in the UK

In this guide, we’ll help you to get an idea of how much you’ll pay for a loft conversion by breaking it down into sections:

  1. Types of loft conversion

  2. Material costs for loft conversions

  3. Will I need planning permission?

  4. Cost example of a loft conversion

  5. How long does a loft conversion take?

Cost of a loft conversion

Types of loft conversion

Loft conversion flat

How much a loft conversion costs will depend on the type of conversion you’d like. There are a few different types to consider:

Roof light conversion

A roof light, or Velux, conversion is usually the most cost-effective type of loft conversion. It’s also the least disruptive type as it involves adding a skylight window (the best-known brand is Velux), laying a suitable floor and putting in a staircase for access. This type of loft conversion is perfect if you want to use the space as a home office or separate living area for older children. You can find a builder to fit a Velux roof for around £30,000.

A roof light conversion is likely to take between 4 and 7 weeks, depending on the size of your loft.

Dormer

A dormer loft conversion is the most common type of loft conversion. It involves a builder extending your existing roof with vertical walls, so you get more floor space and can add more windows. Most properties with sloping roofs are suitable for a dormer conversion, but you should always check with a structural engineer or architect if you’re unsure.

Dormer conversions are ideal for creating an extra bedroom with an ensuite. The extra space and additional windows allows for more light to come in, so the room will feel even larger.

Expect a dormer loft conversion to take between 6 and 9 weeks.

Hip to gable conversion

A hip to gable loft conversion involves replacing one side of your sloping, hipped roof with a vertical end wall (a gable end), which increases the amount of space you have in your loft. Hipped roofs tend to have limited floor space so having a hip to gable conversion will help you to fit in a staircase alongside your living space without it feeling cramped.

However, it’s worth bearing in mind that hip to gable loft extensions are classed as major roof alterations, so you’ll need to apply for planning permission. You can also only have a hip to gable conversion if your house is detached or semi-detached. They generally take between 6 and 9 weeks to complete.

Mansard loft conversion

Mansard loft conversions are typically the most expensive type of conversion. They have sloping walls and a flat roof, making them a versatile type of attic extension that can work for lots of properties. You can also ask an architect to design a mansard extension to match your home so it doesn’t look out of place.

Since you’ll need to change the roof a lot, a mansard loft conversion is the most expensive type and you’ll also need to apply for planning permission before any work can begin.

Mansard loft conversions take anywhere between 8 and 11 weeks to complete.

Bungalow loft conversions

It’s not uncommon for bungalow owners to decide to convert their lofts since there is so much space in the roof. You could create extra space for bedrooms, living areas and bathrooms - whatever your family needs!

Since bungalow lofts are larger, the average cost of a conversion is higher than for two-storey homes. They also take longer to finish - around 10 to 12 weeks.

Material costs for loft conversions

loft conversion windows

Since you’re creating a whole extra room for your house, there are a lot of material costs to think about. These include:

Note: due to Covid-19 lockdowns and Brexit shortages, material prices are currently higher than usual. You might find that you also have a longer wait for materials to arrive, so it’s worth factoring this into the time your loft conversion takes.

Loft conversion window costs

If you want to use your new attic conversion as a proper room, you’ll want plenty of light coming in through windows. Speak to your builder or architect about the amount of windows they recommend you should have. The cost of your windows will depend on the type you’ll need. If you’re having a dormer loft conversion, you’ll want specific dormer windows, but you may want roof lights for other types of loft extension.

Roof lights are often referred to as Velux windows, but this is just one brand. These windows fit into your roof and can be manually controlled or operated using a remote.

Window type Average cost per window
Dormer £150-£300
Roof light (Velux) £320-£550

Loft conversion flooring costs

Flooring is one of the most important costs to consider when it comes to furnishing your loft conversion. What kind of style do you want? Would you like real wood, laminate or carpet? These days, there are lots of options out there and they don’t have to break the bank.

Here’s a quick summary of the costs of different types of flooring:

Flooring type Average cost per m2
Vinyl £6-£14
Laminate £7-£25
Carpet £5-£30
Hardwood £35-£45

Costs of stairs for your loft conversion

You’ll need to consider the cost of your stairs if you want to access your loft conversion! Do you want to go for a traditional, understated look or a more modern aesthetic? Whatever you choose, there’s a cost involved and it’s one you don’t want to scrimp on for safety as well as style.

Stair material Average cost per staircase
Softwood £380-£800
Hardwood £1,400-£1,500
Metal £1,000-£3,000
Glass £2,500-£4,000

Costs of lighting for your loft conversion

The angle of the roof can make loft conversions quite dark, so you’ll want to consider lighting carefully. When you furnish your room, you might want to add table or floor lamps, but we’ll focus on the lighting you’d need an electrician to wire in for you.

You’ll need to decide whether you’re happy with standard ceiling lights, like spotlights and pendants, or whether you’d like to splash out and get smart lighting that you can control with your smartphone.

Lighting type Average cost per fitting
Hanging pendants £15
Spotlights £30-£60
Smart bulbs £15-£170

Loft conversion heating costs

You’ll need to ensure you can heat your loft conversion efficiently if you want to use it as an extra living space. These days, lots of people go for underfloor heating since you can power it using solar panels, but you’ll need to have this installed before your floor is laid. Many people opt to add radiators to their current gas central heating system.

Make sure you check that your current boiler will be able to cope with additional radiators - otherwise you may need to factor in the cost of a new boiler too.

Heating type Average cost
Standard horizontal/vertical radiators £50-£900 per radiator
Electric radiators £90-£400 per radiator
Wet underfloor heating £60-£80 per m2
Dry underfloor heating £30-£40 per m2

Loft conversion insulation costs

You’ll need to consider the cost of insulation for your loft extension as you want to make sure you don’t lose too much heat through the roof and walls. How much it sets you back will depend on the type of insulation you choose.

Insulation type Cost per m2
Loose fill £5-£15
Sheet £15-£25
Blanket £12-£27

Will I need planning permission for my loft conversion?

Most roof light and dormer loft conversions fall under permitted development rules and therefore you won’t need to apply for planning permission. However, if you’re opting for a hip to gable or mansard loft conversion, you will need to apply for planning permission as these types of extensions are considered as major roof alteration works.

Remember, even if you don’t need planning permission for your loft conversion, you’ll still need to get it inspected by your local building control. Submitting your plans and having inspections costs between £400 and £800.

Cost example for a loft conversion

A loft conversion is no small project and there are lots of different parts required to make the room habitable. Take a look at the below table to give you an idea of the supply costs for a 30m2 conversion:

Materials Cost (not including labour)
Velux windows/roof lights £1,200
Flooring £500
Stairs £1,320
Lighting £375
Radiators/heating £1,000
Insulation £320
Electrics £300
Structural beams and joists £2,500
Ensuite £4,500
Decorating materials £1,000
Basic plans £600
Building regulations £600
Party wall survey £200
Total £14,415

How long does a loft conversion take?

How long your loft conversion takes will depend on the type of extension you go for and how big it is. To give you a rough idea, we’ve put together the time it takes to complete each type of small, medium or large loft conversion.

Loft conversion type 20m2 30m2 40m2
Roof light 4-5 weeks 5-6 weeks 6-7 weeks
Dormer 6-7 weeks 7-8 weeks 8-9 weeks
Hip to gable 6-7 weeks 7-8 weeks 8-9 weeks
Mansard 8-9 weeks 9-10 weeks 10-11 weeks

Get competitive quotes

Make sure you get a range of quotes for your loft conversion so you can hear from a variety of builders to see what they would do with the space. Getting more than one quote protects you from being overcharged and also from being undercharged and being left with poor workmanship.

Post a job on HaMuch to get quotes from reputable builders in your area.


Estimates for common extension builder jobs;

Rates for other trades

Loft conversion cost in the UK
Loft conversion cost in the UK (excluding VAT or callout charges)
Location in UKLoft conversion cost
Loft conversion near London£32,850
Loft conversion near Birmingham£30,525
Loft conversion near Glasgow£32,100
Loft conversion near Leeds£30,150
Loft conversion near Liverpool£30,000
Loft conversion near Sheffield£32,400
Loft conversion near Edinburgh£33,075
Loft conversion near Manchester£30,150
Loft conversion near Belfast£30,000
Loft conversion near Bristol£31,725
Loft conversion near Leicester£29,925
Loft conversion near Cardiff£29,850
Loft conversion near Coventry£30,000
Loft conversion near Bradford£30,300
Loft conversion near Nottingham£31,050
Loft conversion near Newcastle Upon Tyne£31,725
Loft conversion near Brighton and Hove£31,350
Loft conversion near Derby£31,050
Loft conversion near Hull£29,925
Loft conversion near Plymouth£31,200
Loft conversion near Stoke-on-Trent£30,000
Loft conversion near Southampton£31,275
Loft conversion near Northampton£31,575
Loft conversion near Wolverhampton£30,525
Loft conversion near Luton£32,925
Loft conversion near Portsmouth£31,200
Loft conversion near Reading£32,925
Loft conversion near Norwich£29,250
Loft conversion near Milton Keynes£32,700
Loft conversion near Bournemouth£32,100
Loft conversion near Aberdeen£33,900
Loft conversion near Peterborough£32,475
Loft conversion near Bolton£30,075
Loft conversion near Swindon£31,125
Loft conversion near Southend-on-Sea£31,575
Loft conversion near Warrington£30,225
Loft conversion near Oxford£32,400
Loft conversion near Swansea£30,600
Loft conversion near Sunderland£31,575
Loft conversion near Slough£32,925
Loft conversion near Kingswood£31,725
Loft conversion near Telford£30,675
Loft conversion near Cambridge£32,475
Loft conversion near Ipswich£30,225
Loft conversion near Blackpool£29,250
Loft conversion near Middlesbrough£30,900
Loft conversion near Dundee£32,475
Loft conversion near Huddersfield£30,375
Loft conversion near York£29,775
Loft conversion near Poole£32,100
Loft conversion near Watford£32,925
Loft conversion near Newport£30,075
Loft conversion near Colchester£30,375
Loft conversion near Exeter£30,900
Loft conversion near Blackburn£29,850
Loft conversion near Crawley£32,475
Loft conversion near Gloucester£31,350
Loft conversion near Stockport£30,300
Loft conversion near Basingstoke£33,000
Loft conversion near Basildon£32,025
Loft conversion near Cheltenham£32,025
Loft conversion near Gateshead£31,725
Loft conversion near Worthing£31,425
Loft conversion near Rochdale£30,150
Loft conversion near Oldham£30,300
Loft conversion near Chelmsford£31,950
Loft conversion near Birkenhead£30,000
Loft conversion near Maidstone£32,475
Loft conversion near Gillingham£32,175
Loft conversion near Salford£30,150
Loft conversion near Solihull£30,225
Loft conversion near St Helens£29,925
Loft conversion near Worcester£30,600
Loft conversion near Lincoln£29,625
Loft conversion near West Bromwich£30,450
Loft conversion near Eastbourne£31,200
Loft conversion near Wakefield£30,375
Loft conversion near Wythenshawe£30,225
Loft conversion near Bedford£33,300
Loft conversion near Hemel Hempstead£33,000
Loft conversion near Preston£29,775
Loft conversion near Stevenage£33,300
Loft conversion near Southport£30,075
Loft conversion near Bath£31,800
Loft conversion near Harlow£32,925
Loft conversion near Sutton Coldfield£30,600
Loft conversion near Darlington£30,675
Loft conversion near Chester£30,000
Loft conversion near Hastings£31,350
Loft conversion near Nuneaton£30,225
Loft conversion near Halifax£30,375
Loft conversion near Hartlepool£31,050
Loft conversion near Aylesbury£32,775
Loft conversion near Doncaster£31,500
Loft conversion near Grimsby£30,225
Loft conversion near Wallasey£30,000
Loft conversion near Stockton-on-Tees£31,050
Loft conversion near Weston-super-Mare£31,050
Loft conversion near High Wycombe£32,850
Loft conversion near Ashford£31,050
Loft conversion near Redditch£30,300
Loft conversion near Wigan£30,225
Loft conversion near Scunthorpe£29,625
Loft conversion near Bury£30,225
Loft conversion near Paisley£32,475
Loft conversion near Bracknell£32,925
Loft conversion near Burnley£30,375
Loft conversion near Rugby£29,550
Loft conversion near Guildford£33,150
Loft conversion near Carlisle£33,750
Loft conversion near Chatham£32,100
Loft conversion near East Kilbride£31,575
Loft conversion near Newcastle-under-Lyme£30,000
Loft conversion near Chesterfield£32,550
Loft conversion near Burton upon Trent£30,900
Loft conversion near Tamworth£30,450
Loft conversion near Shrewsbury£30,000
Loft conversion near Woking£33,000
Loft conversion near St Albans£33,075
Loft conversion near Harrogate£29,925
Loft conversion near Crewe£30,150
Loft conversion near South Shields£31,800
Loft conversion near Craigavon£30,000
Loft conversion near Stafford£30,375
Loft conversion near Rotherham£32,325
Loft conversion near Barnsley£31,800
Loft conversion near Lowestoft£30,750
Loft conversion near Walsall£30,525
Loft conversion near Gosport£31,200
Loft conversion near Dartford£32,775
Loft conversion near Bognor Regis£31,425
Loft conversion near Corby£30,525
Loft conversion near Paignton£31,875
Loft conversion near Maidenhead£33,000
Loft conversion near Rochester£32,250
Loft conversion near Ellesmere Port£30,150
Loft conversion near Loughborough£30,450
Loft conversion near Dudley£30,525
Loft conversion near Dewsbury£30,375
Loft conversion near Mansfield£31,350
Loft conversion near Margate£30,000
Loft conversion near Kettering£30,600
Loft conversion near Cannock£30,600
Loft conversion near Sale£30,150
Loft conversion near Taunton£31,125
Loft conversion near Runcorn£30,150
Loft conversion near Farnborough£33,150
Loft conversion near Tynemouth£31,800
Loft conversion near Hereford£30,375
Loft conversion near Halesowen£30,450
Loft conversion near Widnes£30,075
Loft conversion near Huyton with Roby£30,000
Loft conversion near Scarborough£31,350
Loft conversion near Gravesend£32,400
Loft conversion near Bebington£30,000
Loft conversion near Kidderminster£30,225
Loft conversion near Stourbridge£30,450
Loft conversion near Barry£29,700
Loft conversion near Smethwick£30,450
Loft conversion near Dunfermline£33,000
Loft conversion near Livingston£32,700
Loft conversion near Weymouth£32,550
Loft conversion near Brentwood£32,400
Loft conversion near Barrow-in-Furness£31,575
Loft conversion near Hamilton£29,925
Loft conversion near Canterbury£30,525
Loft conversion near Wellingborough£31,725
Loft conversion near Sittingbourne£31,725
Loft conversion near Macclesfield£30,300
Loft conversion near Bootle£30,000
Loft conversion near Carlton£31,050
Loft conversion near Esher£32,925
Loft conversion near Clacton-on-Sea£30,150
Loft conversion near Lancaster£29,850
Loft conversion near Beeston£30,300
Loft conversion near Banbury£30,900
Loft conversion near Torquay£32,550
Loft conversion near Folkestone£30,450
Loft conversion near Kingswinford£30,450
Loft conversion near Bloxwich£30,525
Loft conversion near Bridgend£29,700
Loft conversion near Welwyn Garden City£33,075
Loft conversion near Lisburn£30,000
Loft conversion near Leamington Spa£29,925
Loft conversion near Washington£31,650
Loft conversion near Tunbridge Wells£32,175
Loft conversion near Kirkcaldy£33,525
Loft conversion near Hinckley£29,850
Loft conversion near Durham£31,425
Loft conversion near Cumbernauld£31,275
Loft conversion near Wokingham£32,925
Loft conversion near Horsham£32,475
Loft conversion near Crosby£30,000
Loft conversion near Yeovil£33,150
Loft conversion near Thundersley£31,725
Loft conversion near Altrincham£30,150
Loft conversion near Willenhall£30,375
Loft conversion near Christchurch£32,025
Loft conversion near Keighley£30,150
Loft conversion near Ashton-under-Lyne£30,225