Loft Conversion Cost

Want to know how much it will cost for a loft conversion?

Having your loft converted is a great way to add value to your home and in this article we breakdown loft conversion prices for different types of conversions, finishes and house types.

But why do this?

Simple. We want to enable anyone who reads this article to get a ball-park figure in mind before hiring a conversion specialist, hopefully saving them from getting ripped off.

By breaking down the the costs of different loft conversions we've made it quick and easy to get a figure in mind for whatever job they need doing.

If you're ready to get a quote for your loft conversion, we can even connect you with local conversion experts. Remember, it's important to get multiple quotes for expensive jobs!

So whether it be a small loft conversion or a dormer with an ensuite, we can help calculate the costs for you below!

How Much Does a Loft Conversion Cost?

The price of a loft conversion will depend on a lot of choices that you make. It is a large project, so the price bands are quite wide. The main factor that will affect the final cost is the type of loft conversion you choose to get.

The average costs for Velux loft conversions are £15,000-£20,000. For a conversion with a dormer, the price range is £30,000-£60,000.

A hip-to-gable conversion will change the shape of the end of your roof and will cost £40,000-£65,000.

The most expensive option is a Mansard loft conversion. This will change the whole shape of your roof and will cost £45,000-£70,000.

When you are looking at these price ranges, remember that the bigger the size and the better the finish, the higher up the price bracket your conversion will be.

There are a lot of decisions you can make to balance your final result with the cost. The most important thing to do is set a budget and then plan, plan, plan.

Loft Conversion Prices

The cost of a loft conversion will depend on a lot of different choices. The two main considerations for the cost are the size of the loft room you will be making and the type of loft conversion you will be getting.

Cost by Size of Conversion

Cost by Type of Conversion

Loft Conversion Cost Breakdown

There are a lot of jobs involved in a loft conversion. The table below gives the cost breakdown for £40,000 conversion. This is to put in about 30m² of loft space and includes a dormer and a roof light over the new staircase. This would cover the electrics and plumbing for a master bedroom with an ensuite.

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Labour Costs and Timescales

There are many different tradespeople involved in carrying out a loft conversion. There will usually be 2-3 people on-site at all times.

The variation in timescale will often depend on how easy it is to schedule all the different tradespeople and may also be affected by the weather.

General Labour Costs and Timescales Based On Conversion Type

Cost Per Hour of Different Tradesmen

Supply Costs

The following table gives you an idea of how much the materials will cost for a loft conversion. There are a lot of materials and, as a result, a lot of options.

Loft Conversion Windows

Loft Conversion Flooring

Loft Conversion Insulation

Loft Conversion Stairs

General Building Materials

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Additional Costs

Here are a few additional costs you might come across when building a loft conversion:

• Plans drawn up by architects: £400 to £1500
• Roof joists: £500 to £1000
• House exterior repainted: £550 to £1500
• House cladding: £2500 to £6500
• House render: £2000 to £8000
• Roof cleaning: £300 to £600
• Replacing roof tiles: £170 to £500
• Underfloor heating: £800 to £7,700
• Wet room: £4000 to £7000
• Boarding and insulating loft: £1500
• Bat survey: £300 to £400
• Building regulations: £40 to £800
• Party wall survey: £150 to £200
• Moving a water tank: £100 to £200
• New boiler: £1500 to £3500

Cost Factors of a Loft Conversion

Because a loft conversion is a big job, there are many factors that will affect the price. Every decision you make about your new loft space will impact on the price.

Type of Loft Conversion

There are four main types of loft conversion. They vary in cost along with how much extra space they provide.

Velux Loft Conversion Cost

These are the cheapest conversions. They are also the easiest and least disruptive conversions to complete. They do, however, provide the least amount of extra space.

No changes are made to the shape of the roof. Windows are just added into the existing roofline. A floor is laid, and a staircase installed. This is only an option if you have a large amount of loft space available.

A Velux loft conversion cost can be between £15,000-£20,000. You could class this as a cheap loft conversion, compared to other options.

Dormer Loft Conversion Cost

With a dormer extension, you will be increasing the amount of headspace available. They create an extra space that protrudes from the roofline. They are more expensive than a roof light conversion, but they will expand the amount of headspace, this makes them suitable for pretty much any home.

The average cost for this type of conversion is £30,000-£60,000.

Hip-to-Gable Loft Conversion Cost

In a hip-to-gable conversion, the shape of the roof is changed. The top line of the roof is extended so that it runs all the way to the edge of the house.

The end result is that instead of having a sloping roof on the side of the house, there will now be a vertical gable that can either be made of brick or tile.

This creates a lot of extra space. It only works in a semi-detached or detached property with a sloping roof. With a detached home, you can convert both sides to create a double hip-to-gable conversion.

The average cost for this type of conversion is £40,000-£65,000.

Mansard Loft Conversion Cost

In the style of a Mansard conversion, the whole shape of the roof is changed. The roof is made to be essentially flat. The new walls come up at 72o. They will appear almost vertical from the outside. In most cases, dormer windows will also be added. This will give the most space but will also be the most expensive option.

The average cost for this type of conversion is £45,000-£70,000.

Type of Roof Tiles

If the conversion involves changing the roof, then the type of tiles matters as some will likely have to be replaced as part of the construction. Houses with slate tiles are typically more expensive to convert than ones with concrete tiles.

Size of Loft Conversion

The bigger the final space will be, the higher the price of a loft conversion. A very small and basic loft conversion can cost as little as £15,000-£17,000. A mid-sized loft conversion making space for a double bedroom with two windows will cost more in the range of £18,000-£25,000. For a large double bedroom with an ensuite, you can expect to pay £25,000-£40,000.

Window Choices

The more window you have, the higher to price will be. Dormer windows cost more than Velux style windows. Each dormer window will cost, on average, £4,000-£6,000. Whereas the Velux windows will cost £800-£1,100.

Internal Walls

If you decide to split your new loft space into multiple rooms, you will need to add in the cost of the extra walls. To put in a stud wall and plater it will cost around £850.

Plumbing Cost

The more plumbing you have, the more you will be paying. There is the cost of the materials as well as the cost of a plumber’s time. Usually, plumbers charge around £35-£45 per hour.

Electrics Cost

The more electrical sockets and light you have, the more you will be paying. Electricians usual charge per hour rather than per job so you can save money by choosing easy to install items. The average per hour cost of an electrician is £50-£120

What's Involved in a Loft Conversion?

A loft conversion is a big job with lots of steps to it. If you get a contractor who is able to get all their tradesmen and labourers organised with no delays, and the weather is on-side for the whole project you can expect the work to go as follows:

Week 1

The first step is to erect the scaffolding. The materials need for the job will be gathered on-site. The roof will be opened up during this week.

Week 2

If the roof structure is changing this will happen next. Extra supports may be installed if needed. For a roof light conversion, the windows will go in now. For a dormer conversion, the dormer will be constructed.

Week 3

The external work will be finished during this week. Any construction on the roof will be finished off, and the tiles replaced and finished. Roof insulation will also be fitted. Internally the loft space will be ready for any plumbing and electrical work that needs to be done.

Week 4

Any windows that haven’t gone in yet will be fitted. The floor will be laid with any ventilation as needed. The plasterboard will be fitted, and any internal walls built.

Week 5

The staircase will go in at this point. If you are having a bathroom fitted, then it can go in at the same time. In this week you should also expect the electrics to be finished. Towards the end of the week the doors will be hung, the plaster skimmed and the skirting fixed.

Week 6

During this week any unfished jobs will be completed. If your contractor is responsible for the decorating that will happen during this week. The scaffolding will also come down during this week.

Of course, this is an ideal schedule. This represents the minimum time for each step and assumes the next job can start straight away.

Do I Need an Architect for a Loft Conversion?

Whether you need an architect will depend on the contractor you choose. Many Loft conversion specialists are happy to work without an architect and rely on their own experience. This can save you a bit of money early on in the process, but ultimately it might lead to problems. Having an architect draw up plans for your loft conversion serves two main purposes.

The first reason to get plans drawn up is that you can be sure the work can be completed and that it will be safe.

The second reason to get plans is so that you have a clear and agreed-upon vision for what the final product will look like. Without plans, it is easy for you and your contractor to be working at cross purposes. With a set of plans drawn up, then you have a record of what you all expect the final project to look like.

The cost of getting plans drawn up depends on how detailed they are. Basic plans cost around £400. More detailed plans can cost up to £1,500. The more detailed plans can be helpful in allowing your contractor to give you an accurate loft conversion price guide.

Loft Conversion Stair Costs

Adding a staircase is now a requirement of any loft conversion. You can no longer simply put in a pulldown ladder. This is for fire safety reasons.

You will need to plan where the staircase will go with care. To make the most of the space you have, you should have the top of the staircase arrive in line with the roof ridge. This means that as you climb, you follow the slope of the roof. If possible, the best place for the stairs is to continue on from your existing staircase.

The cost of staircases varies dramatically. A basic staircase costs around £1,000-£1,200. If you want a custom-made designer staircase, you could be paying as much as £10,000.

There are some rules that govern the design of the staircase

Number of Steps

Building regulations limit you to a maximum of 16 steps in a straight line. Although most loft conversions only require 13.

Size of Steps

The rise of each step can be no more than 22cm. Each step must be at least 22mm deep. Winders, steps that go around the corners but be at least 5cm deep at the smallest point.

Banister

The bannister must be at the height of at least 90cm above the pitch line of the stairs. The spindles must be spaced so that a solid ball with a 10cm diameter can’t pass through.

Space Saving Staircase Costs

A permanent staircase is required by building regulations, but that doesn’t mean that it has to be a traditional staircase. Spiral staircases have a smaller footprint than traditional staircases so it can be a good option in close quarters. The cost of a spiral staircase starts at £1,000.

Space-saving staircases with alternate treads start from £350. The most stripped-down option is to go for a no retractable ladder with a fixed bannister. These are the cheap option, starting at £150.

Can I Build a Loft Conversion Myself?

If you have building experience, then there is no reason why you couldn't have a DIY loft conversion. However, taking on the whole project by your self may be too much for most DIYers.

If you are planning a roof light conversion, that will make no changes to the structure of the roof; then you should be able to carry out a lot of the work on your own. A fully DIY loft conversion costs as little as £6,000. However, it requires a lot of work and knowledge, so it is not for everyone. It will also take a lot longer to complete.

For a loft conversion that involves a lot of structural changes, you would be better leaving that to a contractor. The same is true of plumbing, electrics, and fitting the staircase.

Some parts of the job that any confident DIYer could do are as follows:

Taking on any of these jobs will save you some money. The more you do yourself, the more money you will be able to save. If you do intend to take on some of the work yourself, make sure that you communicate this to your contractor early on. They will need to plan the rest of the workaround you.

Can I Have a Loft Conversion?

Before you start planning your loft conversion, you should find out if you will be able to have one done, and what sort you would be able to have. There are a few things to check that will help to give you an answer.

Check Out The Neighbours

An easy way to see if you can get a loft conversion done is to look for other homes on your street that already have loft conversions. If you find a similar home to yours with a loft conversion, then you are probably good to go. It is also a chance to speak to the owner about their experience; they might have some useful insight for your project.

Measure the Head Space

In order to have a usable space, you need sufficient headspace in your loft. This is the distance between the floor and the ceiling. The minimum height for loft conversion is 2.2m.

It's easy to measure for yourself with a tape measure. This will help you to visualise how much space you will have without making any alterations to the roofline.

Do You Have Space For The Staircase?

It can be easy to forget to consider the space on the floor below the loft conversion. A staircase, no matter how compact, will take up a lot of floor space. You need to identify an area where you are happy to put the staircase.

Is Your Home Listed?

If your home is listed, then you may not be able to get any form of loft conversion. Or you may be limited to a roof light loft, which will not change the shape of the roof or the appearance from the front of the property.

Talk To An Architect

The best way to be certain if your home is suitable for a loft conversion is to get an architect to give you a consultation. They will be able to inspect your property and give you a clear answer on if it is possible to have a loft conversion.

Loft Conversion Ideas

When it comes to a loft conversion, you can use it for whatever you need. Really the only limit is your imagination. It is always a good idea to look at the size and shape of the space you will be creating and then decide what will fit best.

You might end up moving other rooms in the house around as a result. Some of the most common uses for loft rooms are as follows:

Children's Bedrooms

Loft conversions are popular for use as children's bedrooms. If the space, you end up with is quite narrow, then it can work better with a child's bed rather than a full size. A lot of children also like the idea of having a room at the very top of the house.

Master Bedroom with Ensuite

An attic room can feel like a lovely retreat with the sloping ceilings. So, if you have a good-sized space, it is a great place to put your master bedroom. With an ensuite as well it can feel like your own private space in an otherwise busy house.

Guest Room

A loft is a great place for a guest room. For a room that is not used every day, it is easy to close it up when it’s not in use, and your guests can feel like they have their own special place in your home.

Playroom

If you have a growing family, then a whole room dedicated to toys can be a blessing. The sloping ceiling can make for lots of exciting hiding holes, forts, and your children's imaginations can run wild.

Office

Tucked away at the top of the house, a loft room is a great spot for an office. You are lifted above all the family life so are less likely to be interrupted. It also created a bit of separation between work and home for anyone who has to work from home.

Bathroom

Bathrooms are often viewed as solely functional spaces. However, given the blank canvas of a loft conversion, you could create your own decadent spa room.

Home Cinema

The cosy dimensions of a loft room can lend itself very well to a home cinema. Going up the stair to watch a film can make it a special experience.

Do You Need Planning Permission for a Loft Conversion?

In most cases, loft conversion planning permission isn’t needed and are covered by permitted development. Your architect or builder should be able to confirm this for you. However, as long as all of the following provisions apply, you should be safe.

• The total space created from all extensions does not exceed 40m³ for a terraced home and 50m³ for a semi-detached or detached home.
• The conversion will not extend beyond the existing roof slope at the front of the house.
• The maximum height of the roof is not increased.
• Similar materials are used to the existing building.
• No verandas, balconies, or raised platforms are added.
• Side facing windows are not clear glass – the view is obstructed.
• With the exception of hip-to-gable conversions, the roof extension is set back at least 20cm from the original eaves.
• The conversion does not overhang the original walls.

Building Regulations For Loft Conversions

Any loft conversion will need to meet building regulations. It does not matter if planning permission is needed.

Building regulations are about making sure that the new rooms are safe and structurally sound. You will need to make sure you get this done if you intend to sell the property in the future.

Building regulations will dictate some of the materials that must be used, as well as the construction of the loft space. It will likely affect the layout as well; for instance, you will need to have doors to rooms at the top of a staircase.

Your architect or builder should make sure that any work meets building regulations. You can also expect your contractor to arrange any necessary inspections and visits during the course of the work.

However, make sure you check with your builder that they will do this. You are ultimately responsible for making sure that all the work meets building regulations.

Party Wall Agreement

If your loft conversion affects the party wall (the shared wall) with your neighbour, then you must inform them. This might be the case if you will be removing a chimney that sits against the party wall during your loft conversion.

If you aren't sure, you can hire a party wall surveyor to give you some guidance. This usually costs £150-£200.

If you need an agreement, you will need to notify your neighbour at least 2 months before work starts, but no more than 1 year. It is usually a good idea to speak to them about it first.

After you officially notify your neighbour of the work, they have a few options. They can agree to the work, or they can dissent.

If they dissent, you will need to get an agreement drawn up. This usually costs £800-£1,000. The agreement documents the condition of the party wall. It also sets out conditions identifying responsibility for any damage to the party wall.

In many cases, you can save money by simply talking to your neighbour and come to an amicable agreement. Then document the state of the party wall before you start work.

Benefits of a Loft Conversion

There are a lot of different benefits to adding a loft conversion to your home. So when you are considering the cost of a loft conversion, don’t forget to also consider all of these benefits.

Add Value To Your House

The money that you put into your home in the form of a loft conversion will be reflected in the resale value of your home. There are few improvements you can make to a home that offers the same value as a loft conversion does.

Avoid the Cost of Moving

If you are outgrowing your current home, then your only options are to move or the extend your home. A loft conversion offers you a way to get more space without the cost and hassle of moving.

Adding Natural Light

When you get your loft converted you can take the opportunity to get windows fitted over the stairway up. This will allow natural light to filter into your home.

Energy Efficient

As part of your loft conversion, you will have to put in insulation. This is required by building regulations. However, this does mean that you will most likely be making your home more energy efficient and may even find that your heating bills decrease.

Grow Without Losing Outdoor Space

When you have to choose between moving or extending your home because of a growing family, the last thing you want to do is give up garden space. A traditional extension eats up your outdoor space. With a loft extension, you gain more space in your home without sacrificing your garden. A perfect choice for a growing family.

Will a Loft Conversion Increase My House Value?

It is widely agreed that a loft conversion is the best value for money option in terms of home improvement. There is no doubt that the extra space afforded by a loft conversion will add value to your property. On average, a loft conversion will increase the value of a property by 22%.

If your aim is to increase the value of your property, then you should do some research before you start. In most areas, there is a ceiling to the house prices. For example, in your area, houses might sell for a maximum of £350,000.

If you spent £320,000 on your home, then there is no point in spending more than £30,000 on your loft conversion. Spending more than that will not increase the value of your home further. So, make sure to do some research to help you fix your budget.

Different Loft Conversion Options

There are four main types of loft conversion available. Which one you choose will depend on how much loft space you have to start with and how much you are willing to spend.

Roof Light Conversion Cost

This is the simplest type of loft conversion. No changes are made to the shape of the roof. Windows are just added to let light in. The average cost for this type of conversion is £15,000-£20,000.

Pros

• ✔ Cheapest option
• ✔ Least disruption

Cons

• ✖ Only possible if there is already a lot of headroom

Dormer Conversion Cost

A dormer window is added, which changes the shape of the roof and creates more headroom. The average cost for this type of conversion is £30,000-£60,000.

Pros

• ✔ Creates more space
• ✔ Suitable for any home

Cons

• ✖ More expensive

Hip-to-Gable Conversion Cost

The shape of the roof is changed significantly. The sloping roof at the side of the house will be made vertical. The average cost for this type of conversion is £40,000-£65,000.

Pros

• ✔ Creates lots more space

Cons

• ✖ Big project
• ✖ Much more expensive

Mansard Conversion Cost

The roof is changed to be essentially flat. The new walls are steeply slopped up at around 720. The average cost for this type of conversion is £45,000-£70,000.

Pros

• ✔ Give the most space possible

Cons

• ✖ Most expensive option
• ✖ May require planning permission

Can I Have a Loft Conversion in My Bungalow?

Loft conversions are possible in bungalows. If you have a lot of headspace in the loft, you can have a simple roof light conversion. Otherwise, you can choose either a dormer or a hip-to-gable conversion.

The costs of loft conversion are no different for bungalows than two-storey houses. So, the average price of a loft conversion for a bungalow ranges from £15,000 to £65,000 depending on the type of conversion you choose.

How to Keep Down Costs of a Loft Conversion

A loft conversion can be an expensive project to embark on. Here are a few things you can consider to help keep your loft conversion price down.

Take On The Project Management

A loft conversion will require the services of a lot of different tradesmen. In most cases, you will hire a lead contractor who will also project manage the whole process. This involves coordinating the deliveries and the tradespeople so that all the work is completed in order.

You will pay your contractor extra for them to take on this role. If you have the time to stay on-site and manage the project, this can save you between £1,500-£10,000 depending on the scale of the job.

DIY Parts Of The Job

Taking on as many of the jobs as you can will save you money. Even just doing the decorating can save you as much as £2,000.

Plan Well

The best way to keep costs down during a loft conversion is to plan out everything that you want in great detail before you even begin. The highest costs arise when you make a decision midway through the project. Getting an architect to draw up detailed plans can actually help with this and save you money in the long run.

Fix Your Budget and Stick To It

Be strict. Decide how much you want to spend on your loft conversion, and then stick to it. This rolls into planning. You need to decide where and how you want to spend your money before work begins. That way, you don't end up overspending on items.

Possible Issues You May Come Across When Converting a Loft

Because the scope of the work is quite large, there are a lot of opportunities for problems to arise. In most cases, good planning will save you from a lot of the most common pitfalls. Here are a few things to look out for.

Party Wall Disagreements

If your neighbour objects to the work or claims that you have caused damage to the party wall during the work you can suffer delays and legal expenses. To avoid this, you should make sure to speak to your neighbour before work begins.

If you anticipate there might be a problem, make sure to get a party wall agreement in place at least 2 months before you start work, but no more than a year early.

Finding Asbestos

If you have an older home, it is possible that you might come across asbestos in your loft space. Finding asbestos unexpectedly can be a problem. If your home is older and might have asbestos, make sure to get it surveyed before you begin any work.

Furniture That Doesn’t Fit

Your choice of staircase might limit what furniture you can out up in your loft. If you have your heart set on a specific piece that is quite large, then you should speak to your contractor early on. They might be able to arrange to have the furniture taken up before the bannister, or the door frames are built.

Fixtures That Don’t Fit

If you are sourcing the fixtures like baths, showers and sinks, you can sometimes find that they don't fit in the room. Make sure to start planning early. You should especially consider where the water supply will be, and how much space you have for doors to open etc.

Missing Planning Permission

If you need planning permission, because of the scope of the work or because the building is listed, then it can be very expensive to solve. You might even end up having to undo all the work.

If there is any chance you might need planning permission, you should speak to the local council. You can get a notice of lawful development for £100-£400. This will protect you in the future from any disputes.

Cost of Removing a Loft Conversion

If a loft conversion does not meet building regulations, then you may wish to ‘remove it’. It depends on what sort of loft conversion it was, and how difficult it would be to get it to meet building regulations.

The simplest option would be to remove the staircase and replace it with a standard loft access hatch. The cost for this would be around £500-£1,000.

Hiring a Loft Conversion Specialist Checklist

When you are hiring a contractor for a loft conversion, you will need to have faith in them. It is a big project and an important decision.

Here are some things to look for to help you make your decision:

• They should be willing to show you around previous projects. When they do, speak to the owners and ask about their experience. Ideally, you would want to see a recently completed job as well as one that was done some time ago. This will give you a good idea about the quality of the work you can expect.
• Ask to speak to a few of their previous clients, if they are happy to give you lots of names that is always a good sign. When you speak to their previous clients, just check what their relationship with the contractor was like.
• Make sure that your contractor is willing and able to give you a full breakdown of all the costs when they give you their loft conversion estimate. That way, you are all in agreement about the work to be done as well as the costs.
• A good sign is a contractor who takes notes when you discuss what you want doing. It means that things are less likely to get forgotten about.
• Check who will be responsible for organising building control visits. Most contractors will do this but make sure it is clearly agreed as it is your responsibility.

FAQs

Sources

https://www.planningportal.co.uk/info/200130/common_projects/36/loft_conversion/3
https://www.which.co.uk/reviews/loft-conversions/article/loft-conversions/loft-conversions-step-by-step-guide
https://www.gov.uk/party-walls-building-works
https://hoa.org.uk/advice/guides-for-homeowners/i-am-improving/party-wall-agreement/
https://www.self-build.co.uk/how-convert-loft/
https://www.theguardian.com/money/2016/mar/27/home-extension-or-loft-conversion-can-add-20-to-house-value
https://www.homebuilding.co.uk/a-typical-loft-conversion-schedule/
https://www.idealhome.co.uk/project-planning/loft-conversion-ideas-70356
https://www.velux.co.uk/roof-window-configurator