Last updated on May 16th, 2024
How much does a loft conversion cost in 2024?
Fast Facts
- The average cost of a 30m2 loft conversion in the UK can range from £27,500 to £75,000+
- Loft conversion costs vary massively depending on the type and size of conversion
- Contact local loft conversion experts for their professional advice and guidance
If you’re looking to gain extra space in your home then a loft conversion can be an excellent solution. Not only will it give you extra space but it can also add value to your property.
In this guide, we’ve broken down the different elements of a loft conversion so you can see the prices associated with each part of the project.
By having an idea of the cost to convert you can make sure you’re being quoted fair prices by local suppliers and tradespeople.
How much is a loft conversion in the UK?
| Type of loft conversion (30m2) | Average cost | Timescale (weeks) | Cost range - Low | Cost range - High |
|---|---|---|---|---|
| Velux | £27,500 | 4-6 | £22,500 | £30,000 |
| Dormer | £50,000 | 10-12 | £40,000 | £60,000 |
| Hip-to-gable | £60,000 | 10-12 | £50,000 | £70,000 |
| Bungalow (50m2) | £75,000 | 10-12 | £62,500 | £87,500 |
| Modular | £45,000 | 2-3 | £30,000 | £60,000 |
| Mansard | £65,000 | 8-10 | £50,000 | £80,000 |
| Shell | £30,000 | 8-10 | £22,500 | £37,500 |
Our costs are ballpark averages – get a local tradesperson to quote now
On average, a typical UK loft conversion will cost somewhere in the region of £27,500 to £27,500.
The exact price tag can vary considerably depending on the size and complexity of the project.
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Basic loft conversion cost
If you have budget limitations and need to keep costs down, a Velux or shell loft conversion might be good options for you.
A typical shell or Velux loft conversion cost starts at around £22,500.
It’s worth discussing options with local loft conversion specialists to understand what a basic loft conversion costs in your area.
If a basic loft conversion is out of your budget, there’s another option. You may want to consider boarding your loft to maximise the attic space for storage.
What’s included in the loft extension cost?
The table below shows an example breakdown of the costs of a 30m2 loft extension project.
| Job | Average cost (30m2) |
|---|---|
| Project management | £4,000 |
| Scaffolding (excludes temporary roof) | £4,750 |
| Internal preparation | £7,000 |
| Alterations to roof structure | £5,000 |
| Steelwork to support structural changes | £6,000 |
| Roof coverings | £8,250 |
| Electrics and plumbing | £3,250 |
| Joinery (excludes staircase) | £4,500 |
| Staircase | £2,750 |
| Plastering | £2,750 |
| Decoration | £1,750 |
| Total | £50,000 |
It’s important to factor in all of the types of costs above – and there may be more.
As a starting point, we recommend speaking to experienced local loft conversion experts near you. They’ll be able to provide professional advice and guidance on all the loft extension costs involved.
What is the average cost of a loft conversion in the UK?
The size and type of loft conversion you choose are the two most influential factors that will affect the final attic conversion cost.
Based on a 30m2 loft space, here are the average loft conversion costs in the UK:
- Velux loft conversion – £27,500
- Dormer loft conversion – £50,000
- Hip-to-gable loft conversions – £60,000
- Bungalow loft conversion (50m2) – £75,000
- Modular loft conversion – £45,000
- Mansard loft conversion – £65,000
- Shell loft conversion – £30,000
Not sure which type of loft conversion is right for you and your home? Well, you’re in luck. We’ve put together this guide for you: Types of loft conversion: what’s best?
Factors affecting loft or attic conversion costs
Some of the most important factors that will affect the total cost of your loft conversion are:
- Size of loft
- Existing roof structure
- Type of loft conversion
- Style and quality of finishings
- How long the project takes
- Where you live
In general, the bigger the loft conversion and the higher quality of the finishes the bigger your budget will need to be.
Costs for different types of loft conversion
Loft conversion semi-detached house cost
The average cost for loft conversion on a semi-detached house is around £50,000.
The loft conversion cost for semi-detached houses will depend on the style of roof you opt for.
The easiest and most cost-effective option is to install roof light windows without making structural changes to the roofline.
However, if you do want to create a new bedroom and en-suite under the roof, there is the option of rebuilding the side slope roof as a vertical gable end.
The idea here is to create more internal loft space by extending the property by creating a hip-to-gable roof.
How much does a detached loft conversion cost?
The average cost of a loft conversion on a detached property is £62,500.
Homeowners angling for loft conversion on a detached property will typically employ a team of specialists to rebuild the rear roof slope as a gable end and adjust the side roof slope to have a flat roof dormer.
Velux roof windows will be fitted to the front roof slope. These structural changes will increase loft space considerably, allowing the space for a new bedroom and staircase.
The total price for the job will usually be higher than the semi-detached house loft conversion cost but will be returned in an increased property value.
How much does a Velux loft conversion cost?
The average Velux loft conversion cost in the UK is around £27,500.
Velux loft conversions are the cheapest and easiest to do, as they involve the least disruption to the existing loft space. The only downside is that they provide the least amount of additional space to the property.
Because you don’t change the roof structure, a Velux loft conversion is only really suitable for properties with large existing loft spaces.
How much does a dormer loft conversion cost?
The average cost of a loft conversion for a dormer is about £50,000.
If you’re looking to gain some headspace with your loft conversion, a dormer style could work well. By creating dormer window structures that protrude out of the existing roof, you gain valuable additional space.
How much does a hip-to-gable loft conversion cost?
The average cost of a loft conversion on a hip-to-gable is roughly £60,000.
A hip-to-gable loft conversion involves altering the shape of your roof structure to gain space. The existing top line of the roof is extended to the edge of the building, giving an additional box effect to the roof.
This type of loft conversion is only suitable for semi-detached or detached properties with sloping roofs. Some homeowners in detached houses will do a double hip-to-gable loft conversion to add space to both sides of the roof.
Bungalow loft conversion cost
The average cost of a loft conversion on a bungalow is around £75,000.
Due to being a single-storey property, bungalows are perfect candidates for loft conversions. Converting the loft into extra space for bedrooms, living space or bathrooms can make bungalows much more spacious.
Generally, bungalow lofts are larger in area than regular houses and so come in slightly higher in cost.
Mansard loft conversion cost
The average Mansard loft conversion cost is around £65,000.
With a Mansard loft conversion, the whole shape of the existing roof is changed. You end up with an essentially flat roof and vertical outer walls.
This type of loft conversion will give you the most space but consequently is one of the most expensive to do.
Terraced house loft conversion costs
The average cost of a terraced house loft conversion will depend on the type of conversion that is carried out. You can opt for a simple Velux loft conversion, which is the simplest and cheapest option.
The cost of a Velux loft conversion in a terraced house is around £27,500.
A dormer loft conversion in a terraced house will cost in the region of £50,000. Alternatively, a Mansard loft conversion is the most extensive option – with an average cost of around £65,000.
However, for a terraced house, a Velux conversion doesn’t usually provide enough room to make proper use of the loft space.
To add real usable space and open up your loft to potentially being used for one or two rooms, you’ll need to spend a little more.
It’s also important to remember that there are a lot of factors that will influence the cost of a loft conversion in a terraced house, such as property size, the complexity of design, and the quantity and quality of materials used.
Modular loft conversion cost
The average modular loft conversion cost is about £45,000.
A modular loft conversion involves using a prefabricated unit that is built off-site. It’s effectively a modular construction that is built and then delivered to the property and attached to your existing roof space.
Although they may seem like a quicker, easier-to-install loft conversion, they aren’t as straightforward as they seem.
Your loft will often need to be cleared out a lot earlier than a traditional loft conversion as the company building the module will need easy access to take precise measurements.
Modular loft conversions are more affected by bad weather, and can cause more disruption to your neighbours – you may need to obtain a road closure permit for the loft delivery.
Shell loft conversion cost
The average shell loft conversion cost comes in at around £30,000.
A shell loft is a basic loft conversion where all major structural work is carried out, including the new structural floor, joists and dormer(s). The interior design and finishes are then left for the homeowner (or another third-party tradesperson) to complete.
This type of conversion is perfect for homeowners who love DIY or have a limited budget. As the most basic loft conversion, the cost is generally more affordable.
DIY / part loft conversion cost
The average cost of a part loft conversion is typically in the region of £30,000.
If you’re working with a strict budget you may want to look at doing a DIY or part loft conversion to save money.
A part loft conversion is where you hire professionals to create the shell (or ‘skeleton’) of the new loft space, including stairs, flooring and wall structures. You then complete the rest of the conversion work yourself.
Loft conversion cost calculator
Due to the nature of loft conversion projects, it’s tricky to provide a clear calculation for the total cost.
That said, we’ve put together some rough costs per square metre to help you calculate the cost of your loft conversion:
- Velux loft conversion – £920 per m2
- Dormer loft conversion – £1,670 per m2
- Hip-to-gable loft conversion – £2,000 per m2
- Bungalow (50m2) – £1,500 per m2
- Modular loft conversion – £1,500 per m2
- Mansard loft conversion – £2,170 per m2
- Shell loft conversion – £1,000 per m2
Once you measure the estimated floor area of your loft space that you’re converting you can use the above figures to work out the total cost.
As always, for accurate loft or attic conversion costs in your area, we recommend speaking to local loft conversion specialists near you.
Breakdown of loft conversion costs
To help you budget for the different aspects of your loft conversion project, we’ve provided a breakdown of average costs for a typical loft conversion in the UK.
For this cost breakdown, we’ve based it on a £50,000 conversion to create a loft space of approximately 30m2 with a dormer and a roof light.
Loft conversion stairs cost
The staircase is one of the fundamental elements in a loft conversion, and there are a variety of options available at varying costs. For this guide, we’ve based the costs on price per m2.
A basic staircase will cost around £1,000 - £1,500. If you want custom-built stairs you’ll be looking at £5,000+.
For a spiral staircase, the average cost is around £4,000 – £7,950.
For homeowners who want a slightly quirky set of stairs, the average cost of alternating treads is about £400 - £850 per tread.
Finally, the cheapest option is installing a fixed ladder with a bannister, which costs around £200 - £500 per m2.
To find out more, check out our guide to new staircase costs.
Loft conversion flooring costs
The cost of the flooring for your new loft space will vary, depending on the type and quality you choose.
For an average loft conversion, here are some of the prices for the most popular flooring choices:
- Luxury vinyl tile (LVT) – £10 – £60 per m2
- Wooden flooring – £30 – £80+ per m2
- Carpet – £6 - £60 per m²
- Tiled flooring – £50 - £100 per m2
Loft conversion insulation costs
It’s important to make sure your loft is properly insulated. The different insulation options come at different prices:
- Sheet insulation costs around £35 per m2
- Loose-fill insulation is roughly £12 per m2
- Blanket insulation will set you back about £22 per m2
To find out more, take a look at our guide to loft insulation costs.
Loft conversion labour costs
One of the single biggest costs for your loft conversion project will be the labour involved. Given you’ll need a range of different tradespeople to carry out the different work, the labour costs can quickly add up.
Depending on the type and size of your loft conversion, the average total labour cost is between £14,000 - £35,000.
To give you an idea of hourly rates for the different tradespeople, builders, tilers, plasterers and decorators all charge around £25 - £35 per hour.
Plumbers and electricians come in more expensive at about £35 - £50 per hour.
Other costs for converting a loft
There are a wide range of additional costs that you need to consider when planning the budget for your loft conversion project, including:
General building material costs
Here are the average costs for building materials used for a loft conversion in the UK:
- Electrics – £500 - £1,000
- Structural beams, joists and masonry – £1,500 - £4,000
- Bathroom – £5,500 - £9,000
- Decorating materials – £1,000 - £2,000
- Built-in storage – £2,500 - £10,000
Architect plans cost
Not all building contractors will need full architect plans but it’s always a good idea to get them drawn up so you’re clear on the project scope.
Simple architect plans will cost around £500, with more detailed plans costing up to £2,000.
Want help finding the best local architects? Read our guide on how to find architects near you.
Underfloor heating cost
Installing underfloor heating is becoming more and more popular with British homeowners. For an average loft conversion, underfloor heating will cost between £450 - £1,050.
Bat survey cost
As bats are a protected species, if you think you might have them nesting in your roof you’ll need to get an official bat survey done.
You’ll then get a license to proceed with the loft conversion work. A bat survey generally costs about £400 - £750.
Building regulations cost
If you decide to hire tradespeople who aren’t registered as part of the Competent Tradesperson Scheme then you’ll need to pay for your loft conversion to be approved by Building Regulations. The cost is usually between £500 - £1,250.
Other additional costs
- If you need to move your water tank as part of the loft conversion, the cost is around £750
- Painting the exterior of your house will be about £3,000 – £6,000
- If you need to do the cladding it will cost about £80 – £325 per m2
- Rendering will set you back about £4,000
How to keep costs down for your loft conversion
With a big project like a loft or attic conversion, it’s important to keep your spending under control. Here are some of our top tips for reducing costs when converting a loft:
- Thorough planning – By planning ahead you can foresee the various stages of the conversion and avoid the costs of rectifying unnecessary mistakes
- Hire an experienced local architect – Although it’s an added initial expense, an experienced architect who is familiar with local planning can save you a lot of money in the long run
- Project manage the conversion yourself – If you’re organised, detail-oriented and have the time and energy to take on the project then you can save thousands by being your own project manager
- Incorporate realistic DIY jobs – If you’re a confident DIY enthusiast, you can save money on smaller jobs by doing them yourself (such as painting walls, laying floor tiles or installing shelves and other fixtures)
Reasons to get a loft conversion
There are several great reasons why converting your loft is a good idea:
- Add around 20% value to your home
- Create more living space by making the most of the property you already own
- An extra bathroom built in a loft can be a valuable addition to a family home
- Planning permission isn’t needed for most loft conversions
- Enjoy a room with a view thanks to the new height added by your home
- Build up, not out, so you don’t eat into any valuable garden space you may have
Find the best loft conversion experts near you
Ready to start planning your loft conversion? When it comes to getting quotes, we highly recommend getting at least 3 different quotes. This allows you to compare prices as well as what is included in each tradesperson’s service.
To create your own list of tradespeople to contact for a quote, use our free search tool below by entering your postcode in the box below:
Alternatively, let us help you with our request a quote feature. Simply post the details of your project and we’ll send them to 3 tradespeople for you, so you can sit back and wait for the quotes to arrive.
Hire a registered competent tradesperson
As it’s so important to meet all relevant Building Regulations, always hire tradespeople who are registered as part of the government’s Competent Tradesperson Scheme.
All tradespeople in this scheme will have already proven their ability to carry out certain work to required standards, which means you won’t need to apply for building regulations approval.
Need help finding the best loft conversion specialists? Check out our tips for how to find good tradespeople.
Building Regulations for a loft conversion
Loft conversions will need official Building Regulations approval. That means you need to get a registered building control surveyor to inspect your conversion at various stages of the project.
An experienced surveyor will also issue you a completion certificate following a final inspection once the conversion is complete.
If you live in a semi-detached or terraced property, you’ll need to notify your neighbours before you start any planned building work under the requirements of the Party Wall Act 1996.
Useful loft conversion checklist
- Plan, plan, plan. Loft conversions can be complicated, so it’s important to be in control and plan your loft conversion project
- Calculate your budget as a starting point and plan from there
- Remember to include all potential additional costs
- Factor in contingency for changes and extra costs during the conversion
- Decide what you need the space for and research your options
- Contact your local planning office to confirm if you’ll need planning permission or not
- Speak to local builders for advice and discuss viable options
- Ask friends and family for recommendations of loft conversion experts
- Shop around for fair and competitive prices
- When hiring a professional always choose registered competent tradespeople with relevant loft conversion experience, qualifications and accreditations
FAQs
Do I need planning permission for a loft conversion?
Not necessarily. In most cases, a straightforward loft conversion is considered ‘Permitted Development’, which means it shouldn’t need planning permission.
That said, if you’re planning on extending beyond the specified conditions of Permitted Development, you live in a conservation area, or you have a listed property, then you will need to apply for planning permission.
Also, if you’re planning to alter the shape or height of your roof structure then you’ll also need planning permission. That includes any windows or structural changes that will sit outside of the current dimensions of your roof.
To ensure your loft conversion project complies with all permissions and regulations, we recommend always checking with your local planning office before you begin the project.
What is the cheapest way to do a loft conversion?
As a general rule, the cheapest way of converting a loft is to carry out a Velux loft conversion. Effectively, you’re simply working with the existing dimensions of your attic space by reinforcing the loft floor and installing roof lights.
Typically, a Velux loft conversion costs from around £22,500.
Does a loft conversion add value to a house?
Yes, if done properly, a loft conversion can add up to 20 – 24.5% to the value of your property.
You can find out more in our handy guide: Add value to your home with a loft conversion
What’s the most expensive part of a loft conversion?
Usually, the biggest chunk of your budget will be spent on the labour cost of the contractors you hire. Labour typically accounts for around 30% of the total cost of a loft conversion.
The second most expensive part of a loft conversion is usually materials, which account for around 20% of an average loft conversion. This cost can vary hugely depending on the quality and quantity of materials used.
How much is a loft conversion in London?
As with all home improvement projects, loft conversion costs will vary across the UK. And, as you might expect, in London costs are usually higher.
You can expect to pay the upper end of our cost estimates for converting a loft in a London property:
- Velux loft conversion– 4-6
- Dormer loft conversion – 10-12
- Hip-to-gable loft conversion – 10-12
- Bungalow (50m2) loft conversion – 10-12
- Modular loft conversion – 2-3
- Mansard loft conversion – 8-10
- Shell loft conversion – 8-10
How long does a loft conversion take?
Depending on the size and complexity of the conversion, it should take approximately 6-10 weeks to complete.
That’s from when construction starts, once you’ve obtained any necessary planning permits.
What type of loft cannot be converted?
Although many lofts are suitable for conversion, not all homes can carry out a loft conversion.
Some of the reasons that might stop you from cracking on with a loft conversion in your home are:
- The ridge height of your loft (if you have a low roof ridge height you may need a roof lift loft conversion)
- Any restrictions with roof alterations that apply to the building
- The existing roof/loft structure of the property
- If your home is located in a conservation area
To find out if your home is suitable for a loft conversion, speak to your local planning office or loft conversion experts in your area.
How do people afford loft conversions?
There’s no denying that any loft conversion will need a fairly hefty budget. But, fret not. There are various ways to cover the cost of your loft conversion…
- Save up over time and use your savings
- Take out a loan (secured or unsecured) to cover the costs
- Remortgage your home to get extra budget
- Pay some of the smaller loft conversion costs on a credit card (ideally one that offers deferred payments or 0% interest for a period of time)
Before undergoing any loft conversion project, make sure that can comfortably afford the costs involved.
Did you enjoy this loft conversion cost guide?
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Dave R
ThanQ, very useful to have all of this in one place! Helped me compare loft conversions with the alternative option of raised loft boarding (raised above the insulation).
Sami Fellah
Thanks for displaying all necessary information as it will £££ guide to build a loft conversion.
Robert Kelly
This has been really helpful, especially with the pricing guide for each item involved in the project.
Jacqueline May
Thank you - this is so useful!
Mike C
Excellent Article and very difficult to get this elsewhere!
Paul Harris
Really great to have this article as it is very hard to even get a rough idea of breakdowns easily. And if you home to be able to do some of the work yourself, its great to have some figures. Thanks
Eva Corbett
great and very useful article. it answered lots of questions I had prior to making the decision to go ahead with the conversion