If you’ve run out of floor space in your property and are longing for another room or two, often the best option is to build upwards, into the roof space.This can be tricky, with a myriad of questions and possibilities which can make it hard to know where to even start when planning a job of this scale.
In this article, we’ll be covering:
- How much a loft conversion costs
- What affects the price of a loft conversion
- How to save money when converting your loft
- What a loft conversion involves
- How to find and hire a builder to carry out your loft conversion
If you want a conversion, but haven’t a clue where to start, keep reading to find out everything you need to know and the prices and timescales involved in each aspect.
How Much Does a Loft Conversion Cost?
A loft conversion typically costs between £21,000 to £44,000, but you could easily pay up to £63,000 if you want a particularly large extension.
The estimated cost of a loft conversion by type and time required
|Conversion Type||Estimated Cost||Time Required|
|Roof Light or Velux Conversion||£20,000 to £49,000||4 to 7 weeks depending on size|
|Dormer Conversion||£30,000 to £69,000||6 to 9 weeks depending on size|
|Hip-to-Gable||£40,000 to £70,000||6 to 9 weeks depending on size|
|Mansard||£45,000 to £75,000||8 to 11 weeks depending on size|
For a conversion including a roof light or Velux window, you can expect to pay between £20,000 to £49,000, with a time duration of between four to seven weeks. Velux windows can range in size from 55 x 70 cm to 134 x 160 cm and this will dramatically impact your costing – a smaller Velux window alone can cost £610 to £1,260 whilst a larger window can cost from £760 to £1,520.
A Dormer conversion will cost a little more, coming in at between £30,000 to £69,000, and taking slightly longer at between six to nine weeks. A Dormer conversion is a box-like structure that projects from the existing roofline of the house and is known to increase the value of the property.
For a hip-to-gable arrangement, this will be between £40,000 to £70,000, taking six to nine weeks to complete. This is where the sloping side of the roof is converted to a gable wall to maximise floor space and is a popular choice of conversion.
Finally, the grandest option comes from the Mansard option which can cost anywhere between £45,000 to £75,000, and take up to 11 weeks depending on the size. This is usually built on the rear of the property and the slope of the face softens the outside appearance.
The estimated cost of roof light and dormer conversions by the number of windows/dormers and size.
|Number of Windows or Dormers||Size of Loft Conversion||Size of Loft Conversion|
|2 roof lights||5 metres x 4 metres||£20,000 to £24,000|
|2 roof lights||5 metres x 6 metres||£24,000 to £28,000|
|2 roof lights||8 metres x 12 metres||£40,000 to £45,000|
|4 roof lights||5 metres x 4 metres||£22,000 to £26,000|
|4 roof lights||5 metres x 6 metres||£26,000 to £30,000|
|4 roof lights||8 metres x 12 metres||£44,000 to £49,000|
|1 dormer + 1 roof light||5 metres x 4 metres||£30,000 to £34,000|
|1 dormer + 1 roof light||5 metres x 6 metres||£39,000 to £44,000|
|1 dormer + 1 roof light||8 metres x 12 metres||£55,000 to £62,000|
|2 dormers + 2 roof lights||5 metres x 6 metres||£43,000 to £48,000|
|2 dormers + 2 roof lights||8 metres x 12 metres||£62,000 to £69,000|
For two roof lights, and a loft conversion size of five metres by four metres, you can expect a cost of between £20,000 to £24,000. For a slightly larger space of five to six metres, this price will rise to £24,000 to £28,000, and for an eight by 12-metre space, this will cap at £40,000 to £45,000.
Four roof lights and a conversion space of five by four metres will set you back by £22,000 to £26,000, while the same amount of lights in a space of five by six metres will be between £26,000 to £30,000. For a larger space of eight by 12 metres, this will become £44,000 to £49,000.
Moving onto Dormers, for a five by four-metre space with one roof light, you can expect to be charged between £30,000 to £34,000, while a five by six-metre space will cost you between £39,000 to £44,000. For the larger space of eight by 12 metres, this cost will settle at between £55,000 to £62,000.
If you want to have two Dormers and two roof lights, you can expect to pay between £43,000 to £48,000 for a five by six-metre space, while an 8 by 12-metre space will be between £62,000 to £69,000.
The budget option when it comes to loft conversion is typically to go for a Dormer, or consider adding a Velux window. If you’re after a more substantial conversion and have the budget for it, a Mansard tends to increase the floor space nicely and have a softened and conjoined outside appearance.
What Affects the Cost of a Loft Conversion?
The biggest factor affecting the cost of a lost conversion is what type of budget you have for the project.You will also need to determine whether the space is suitable, your type of roof, and if you’re going to need to seek out planning permission.
The Conversion Size
Simply put, the larger the conversion you want, the more money it’ll cost you. Instead of doing a budget job that isn’t as big as you’d like in the first place, it’s more cost-effective in the long run to save up that bit longer to get the entire job done properly the first time round to remove the need for rebuilds further down the line.
The Conversion Style
There are a few styles to choose from when it comes to loft conversions, all with different prices to help you decide:
- Velux – usually the most affordable option, involving affixing one or two windows to the roof to introduce light. This can cost between £21,000 to £41,000.
- Dormer – a very commonly used loft conversion, the Dormer is a flat-roofed extension that typically has a window.
It’s common to have two of these on one roof. However, side dormers and L-shaped Dormers (an extension added to the rear of the Dormer) are also available.
In the case of the latter, it could result in up to four new rooms. The cost for Dormer conversions ranges from £31,000 to £58,000 for a standard Dormer and £40,000 to £60,000 for an L-shaped Dormer.
- Hip to Gable – either one or both of the end sloping parts of the roof are replaced with a gable wall, which will cost between £42,000 to £65,000
- Mansard – this type of extension is usually the most expensive. A Mansard extension involves replacing one side of the roof with a straight wall and flat roof.
Both sides could be extended, resulting in a whole new storey. The renovation is major and would involve planning permission, and cost between £45,000 to £75,000.
The Roofing Material
Understandably, the material you choose for your roof will affect the price you pay. To read up on different roof types and their associated costs, see our dedicated page on it here.
The Windows and Glazing
Much like the roof material, the type of window or glazing you choose will impact the price you pay.
Choosing between double and triple glazed, or different types of window frames and materials can bump up or reduce costs – for full information, see our dedicated page on new window costs.
The Purpose of the Room
Before building, you must have an idea of what the space will be used for as it’ll directly impact the planning and price you pay.
If you want the space as an extra bedroom or home office, you’ll at least need electrical outputs, so it’s another job to get an electrician involved to send cabling to the right locations.
Obtaining a Party Wall Agreement
Regrettably not as exciting as it sounds, the Party Wall Agreementcan cost up to an additional £1,000 on top of your project fee.
You must let your neighbours know about any work you are to carry out on your home before it gets started. The party wall stands on the land of two or more owners and forms part of a building.
If You Require Scaffolding
Depending on the extent of your conversion, you’ll most likely need scaffolding for labourers to reach the heights necessary to undertake the work.
Your property may also need additional structural support while the work is being completed, so this is usually an inescapable feature of conversion work.
Rubbish Removal and Skip Hire
There will be a lot of masonry debris, along with your existing roof to get rid of while the job is happening. This will likely require the assistance of a skip hire – which can quickly become expensive if it’s at your property longer than anticipated, or filled with restricted items.
If you’d like to know more about how much rubbish and waste clearance services cost, we have a guide for that!
Or, if you’re planning on hiring a skip, see our dedicated page instead.
How Can I Save Money When Converting My Loft?
Converting your loft is one of the more expensive home renovations, but there are some ways to cut costs down.
Part of what escalates costs quickly is the urgency for which you need materials and tools. By purchasing savvily you can be sure to get hold of the items you need at preferable prices to you – and not have your hand forced by your labourer’s deadlines.
By making purchases during sales or percentage off days, you can save a considerable amount of money instead of buying items at full price. All you have to put up with is having a few fittings laying around your home before they’re ready to be used!
It’s not the most glamorous option but if you’re up to the challenge, removing the debris and rubbish accumulated from the job yourself can be a way to cut down on excess rubbish removal costs – and in some instances, a skip hire.
Liaise with your contractors to see what’s possible, and propose what you’d be happy to do up front so they know what your intentions are.
With a lot of upheavals comes a lot of new space to paint, lay carpets and generally finish to make it look neat again.
Instead of hiring the help of a painter or decorator, if you’re up to it, it’s a great idea to do this final step yourself. This way, you’re just paying for the cost of materials and not for the labour costs of anyone else.
Especially if you’re on a road where you have no available parking at your property and have to pay for a parking permit to let the trader park outside, you’ll be thankful to chop this expense out of your projections by finishing up and making good yourself.
Is a Loft Conversion the Best Choice for Me?
Loft conversions take not only money, but time. This can cause severe disruption to your household and may require a lot of planning to organise.
As undertaking a loft conversion is such a big home development project, we’ve compiled this list of advantages and disadvantages to help you decide whether or not contracting a loft conversion is the right decision for you and your home.
|It will provide you with more storage or living space||It's an expensive and time-consuming project|
|It can potentially add value to your property||Your property may not be suitable for it|
|It won't tamper with or overshadow your neighbour's land||You will need to make sure the conversion complies with Building Regs|
|You won't lose any space in your garden to have it installed|
The main advantage of a loft conversion is it will provide you with more storage or living space. You can use your imagination to ensure that your loft conversion best suits your needs and fill the space however appeals to you.
It’s also common for loft conversions to potentially add value to your property, as it provides more floor space and can be a highly-sought after feature.
It also has benefits when it comes to the installation process itself. You can rest assured that a loft conversion won’t tamper with or overshadow your neighbour’s land, and you also won’t find yourself giving up any garden space as you might with a conservatory or glass extension.
A potential disadvantage of loft conversions are how expensive they can be and how time-consuming they can be to complete, as well as causing severe disruption to the home during the process – this may mean you’ll need to find somewhere else to live for the duration of the project.
You will need to make sure the conversion complies with Building Regs which might mean that you find out your property isn’t suitable for a loft conversion at all, which can be a big disappointment if it was a dream project.
What Does a Loft Conversion Involve?
A loft conversion is one of the more complex home renovation jobs out there. Many labourers are involved in the process, all with different jobs and purposes.
The scaffolding is the first job, and once this is in place all the required materials will be brought onto the site in preparation.
The roof will then be opened and if there is a change taking place with the roof structure this will be tackled first, with extra supports added as needed. Any skylights or Velux windows will be installed, and if you’re undertaking a Dormer conversion it will be constructed at this point.
The external work will then be finished with any tiles replaced or repaired and roof insulation fitted. If interior work needs to be undertaken, such as plumbing and electrics, this will take place at this point.
Towards the end of the job, the doors will be hung and any skirting will be added.
How Do I Find and Hire a Builder?
The best way to find a builder for your loft conversion is first to look around you – has someone on your street recently had their loft done, and you like the look of it?
Asking to see the space and, if they’re willing, sharing the name of their contractor can be a great way to find someone reputable to work for you. Not only can you see the proof of their work in the flesh, but you’ll have a recent, up-to-date review of their work from someone you already know – and they’re unlikely to recommend someone that’s no good
When this isn’t possible, you can take your search online. But to save you hours of faffing and flicking between websites, using HouseholdQuotes can help to streamline your search into one query while keeping you on one website.
What’s more, comparing quotes on HouseholdQuotes can help you to save up to 40% off your project fee – which is a lot when it comes to loft conversion prices!
Ensuring the Professional is the Right Fit
As with all home renovations, getting a quote in written format is one of the first major steps in ensuring you get a reputable contractor.
No matter how nice someone may be to your face, whatever you agree verbally is just that – verbal. There’s no way of refuting what someone did or didn’t agree to in those circumstances, so it’s always best to get anything written down to serve as a reference point for both parties.
If the contractor isn’t coming from a word-of-mouth recommendation, it’s best to find out their experience and see some proof of their previous work to make sure they’re a good match for what you’re looking for. When it comes to electricians, it’s best to make sure that the contractor is qualified and listed on the government’s Registered Competent Person Scheme, and that they’re able to give you a BS7671 test certificate once they’ve finished allowing you to pass Building Regulations.
If your friend has recently had a conversion done by a particular trader, asking to see it in person can be a great way to get a tangible feel for the space and if their work is what you’re looking for.
Whenever this isn’t possible, asking the trader for photos or videos of their work is the next best thing, as you can see the proof of their work in reality (and not just what they’ve written about themselves on their website).
Finally, all contractors worth their salt will carry sufficient insurance to cover themselves and you and your home while they work. Asking to see proof of this isn’t a step too far – and if the trader refuses or bucks at you asking, it’s best to step away from that deal, as they could be rogue traders with little care for the outcome for you.
If your existing floor plan is just too small for your family, extending into the roof is a great way to free up some potentially underutilised space in your home.
Here’s our final checklist to make sure you’ve considered all you need to before you get started on this project:
- Scope out what’s right for you: get someone in to take a look at your loft space and make sure there’s enough clearance for a conversion in the first place to save a lot of time (and potential heartache)
- What type is best for you? You may be swayed by your building layout but if you have free reign to choose, you can go between a Velux, Dormer, Hip to Gable or Mansard conversion, each with its associated costs and conditions
- What do you want the room for? A bedroom, bathroom, or study? These conditions will need to be known before work starts to make sure sufficient cabling or pipework can reach the room
- Find a reputable trader using HousehodQuotes – which can also help to save you up to 40%, which is a considerable saving on such an expensive project
- Look forward to relaxing in your newly-created extra space!
Frequently Asked Questions
Do I Need Planning Permission or Building Regs Approval for a Loft Conversion?
If your home is a listed building, as with everything else, you’ll need to inform the planning department of any intended alterations.
If your proposed loft conversion is higher than the original roof or is potentially going to affect the view for those nearby, (as in the case of the Mansard), then neighbours are informed by your local planning authority and given 21 days in which to object.
This can put an abrupt end to your planning dreams – so it’s always best to talk it out with your neighbours before committing to any plans to make sure they’re satisfied you’ve tried to work around their needs, too.
Can a Loft Conversion Increase the Value of My Home?
It’s extra square footage for the homeowner, and if the original house was quite pokey, it’ll be saving them the hassle and upheaval of having the conversion done themselves – so you’re saving them time and effort, which will be reflected in your house price.
Do I Have Enough Space for a Loft Conversion?E
As a rule of thumb, you’ll need at least 2.2 metres from the bottom of the ridge timber to the top of the ceiling joist to make the space usable as a loft conversion. But if you’re in doubt, have someone come round to take a look at the space for you.
What’s the Cheapest Type of Loft Conversion?
These can cost anywhere from £20,000 to £49,000 depending on the size and number of windows you choose.
Is a Loft Conversion Cheaper Than an Extension?
To put things into perspective, a 30 square metre roof light conversion costs between £24,000 and £30,000 depending on the number of windows you choose.
Alternatively, a 30 square metre loft conversion with one dormer and one roof light costs between £39,000 and £44,000.
By comparison, a 30 square metre extension built on a budget costs between £30,000 and £48,000 (not including any finishes). Based on these estimates, a loft conversion could be the more affordable option depending on the size and style you choose.
Not only will the extra accommodation provide you and your family with more breathing space, but your home should also fetch a better price when you come to sell – around 20% more, in fact, according to the HomeOwners Association.
In other words, adding a loft conversion is a win-win – providing you get the renovation right from the start.
Does My Loft Conversion Need to Include a Staircase?
A simple loft conversion staircase can cost from £1,000 to £2,000 whilst a more luxury and bespoke staircase can cost from £5,000 to £8,000+.
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