Loft Conversion Cost

Do you 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 break down loft conversion prices for different types of conversions, finishes and house types.

So, how much will a loft conversion cost?

The average cost of a loft conversion in the UK is approximately £40,000 with prices reaching up to £70,000 and more for large builds or those using high-end materials.

Remember: It's important to request multiple quotes for large projects such as a loft conversion. After all, having your loft converted is an excellent way for homeowners to add extra living space to their homes, but there are certainly a lot of decisions you need to make when planning such a large project.

Our aim is that this guide gives you a quick and easy way to get a ballpark idea of what you should expect it to cost to get the loft conversion that you want.

If you're ready to get a quote for your loft conversion, we can even connect you with local loft conversion specialists. 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 is a Loft Conversion?

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-£30,000. 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-£75,000.

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 start planning.

Loft Conversion Cost by Type

There are four main types of loft conversion available: velux, dormer, hip-to-gable, and Mansard.

Which one you choose will depend on how much usable loft space you have, the type of attic structure, and your budget. The method of construction can also have an impact on your decision.

While you may choose to have the entire project completed at once, there are alternatives that can affect the overall cost. For example, a shell conversion includes only the basic structural work, without the added extras such as electrics, bathroom installation, or decorating.

Meanwhile, a modular loft conversion involves building the main elements off-site and delivering them to the property in one go, offering a faster and often less disruptive process.

In the sections below, we cover the characteristics of these four main options and average costs for a typical loft conversion.

Velux Loft Conversion Cost

Velux loft conversions are the most cost-effective type of loft conversion. They're commonly referred to as skylight or rooflight loft conversions online and by builders.

They're the most straightforward and least disruptive option available. No changes are made to the shape of the roof when converting your attic space in this way. Windows are just added into the existing roofline, the new loft flooring is laid, and a staircase is added.

The downside is that these are only a viable option if you have attic space with sufficient enough headroom, and they also tend to add the least amount of liveable space to a loft.

The average cost of a velux loft conversion that's 20m² is between £20,000 - £30,000. This is still a sizable investment, but more affordable than other options.

Dormer Loft Conversion Cost

Dormer loft conversions are a popular option in the UK, as they give homeowners the opportunity to greatly increase the amount of headroom and space available in their attic.

They create an extra space that protrudes from a sloping roofline. There are various styles of dormer loft conversions - including flat roof, shed, gable-fronted, and hipped roof. Dormer attic conversion prices present a distinctive visual adjustment to your property, but improve your home's aesthetic when done right.

The average cost of a dormer loft conversion that's 20m² is between £30,000 - £40,000. This is more expensive than a rooflight loft conversion, but might be necessary if you don't have enough headroom in your attic space.

Hip-to-Gable Loft Conversion Cost

Hip-to-gable loft conversions are sometimes referred to as gable-end or gable-wall conversions by builders.

In a hip-to-gable conversion, the shape of the roof is significantly altered. The sloping "hip-end" is replaced with a vertical gable wall.

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. However, it only works in a semi-detached or detached property with a sloping roof. With a detached home, you can also convert both sides to create a double hip-to-gable conversion.

The average cost of a hip-to-gable loft conversion that's 20m² is between £40,000 - £65,000. This is another step-up in price when compared to average rooflight and dormer attic conversion prices in the UK.

Mansard Loft Conversion Cost

Mansard loft conversions involve changing the whole shape of the roof, which is essentially modified to be almost completely flat. The walls will also be almost vertical (70-degree angle) and, in most cases, dormer windows can be added.

Because Mansard loft conversions cause significant visual change to a property's exterior from these structural changes, they typically require the owner to apply for planning permission. Whereas dormers tend to fall under permitted development, and therefore permission is not needed.

The average cost of a Mansard loft conversion that's 20m² is between £45,000 - £75,000.

While the most expensive option, they provide homeowners the opportunity to maximise the amount of floor space provided by their loft conversion.

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

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.

On this example, labour and project management would amount to approximately 60% of the total cost for the entire project. Around 25% would cover the cost of materials, with 8% for scaffolding and the remaining balance of 7% of the budget reserved for any unexpected additional fees.

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. However, as a guide you should anticipate labour fees (including project management) to account for around 50% to 60% of your total cost.

General Labour Costs and Timescales Based On Conversion Type

Cost Per Hour of Different Tradesmen

Supply Costs

The following tables give an idea of how much the materials will cost for a loft conversion. There are a lot of materials and, as a result, many different options available. Although in total, supply costs (not including scaffolding) will amount to around 25% of your build, the majority of the total cost going towards labour and project management.

Loft Conversion Windows

Loft Conversion Flooring

Loft Conversion Insulation

Loft Conversion Stairs

General Building Materials

Additional Costs

Here are a few additional costs you might come across when building a loft conversion, although please note these may not all be relevant to your specific build and prices may vary depending on the extent of the work involved:

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 Roof Tiles — If the conversion involves work on the roof, it's likely tiles will need to be replaced along the way. The material and style will impact the cost.
• Size of Loft Conversion — Small, basic loft conversions can cost as little as £15,000-£17,000. A mid-sized loft conversion such as a 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 - 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. It will cost around £850 to put in a stud wall and plaster.
• Plumbing Cost — Usually, plumbers charge around £35-£55 per hour (more in areas such as London) although you will also need to factor in material costs.
• Electrics Cost — Electricians usually charge per hour rather than per job, the average cost of an electrician is £50-£120 per hour (again, this may be higher in certain areas).

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.

Rooflight 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 £45,000-£75,000.

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 sloped up at around 72 degrees. 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

Loft Conversion Methods

Following the different types of loft conversions, the method in which they're built can also impact the price. There are two main types of structural methods used in this type of build:

Shell Loft Conversion

If you wish to keep costs down to a minimum, then a shell conversion might be the best option. In this type of project, the construction company only provide the structural elements of the build (framework and supports, along with installing the likes of stairs and windows).

All the internal fixtures and fittings are then left to the homeowner. Allowing you to complete the painting and decorating at your own leisure, or keep labour fees to a minimum by hiring other tradesmen such as plumbers or electricians at a later date.

By removing the final stages of the build, the cost of a simple shell conversion can start from as little as £10,500. However, for larger or more complex bespoke designs, costs can reach up to £52,500.

Modular Loft Conversion

This type of conversion uses pre-fabricated designs that are built prior to being installed and then shipped into place. This means they arrive onsite with the main components ready-made, and therefore cause less disruption during the building process.

Other benefits include not only potentially saving money, but the process enables modular loft conversions to be precision built quicker and with greater quality control.

The downside to modular units being there's often less flexibility, and (unlike shell conversions) they are only really suitable for dormer loft conversions. Cost-wise, prices range anywhere from approximately £16,500 to £90,000.

It's also important to note there will be delivery costs included in a modular loft conversions as they are transported and then put in place via a crane. Therefore delivery fees may be higher, especially in areas such as London and the South East.

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.

Having an architect draw up plans for your loft conversion serves two main purposes:

1. Firstly, to get plans drawn up is to ensure that the loft conversion work can be completed safely.
2. Secondly, 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, you have a clear record of what the loft conversion should look like - there will be no ambiguity whatsoever.

The cost will depend on how detailed they are, although as a guide - basic plans cost around £400 and more detailed versions can cost up to £1,500. The more detailed plans can be helpful in allowing your contractor to give you an accurate quote for your loft conversion.

What's Involved in a Loft Conversion?

A loft conversion is a big job with lots of steps to it.

If you hire a contractor who is able to get all their tradesmen and labourers organised without any delay, along with the weather being onside for the whole project, you can expect the work to go as outlined below.

Although this can vary depending on the size of the project and the work involved.

For example, if you're only having a shell conversion fitted, then process that include internal work or adding finishing touches can be carried out a later date. Alternatively, if you have chosen a modular conversion, there is far less work carried out onsite as everything arrives pre-fabricated.

• Week 1 - Preparation

  The first step is to erect the scaffolding, along with having any materials and equipment required delivered to the site. The roof will also be opened up during this week.

• Week 2 - Roof Work

  Modifications will be made to the roof if required, plus extra supports may be installed where needed. For a rooflight conversion, the windows will go in at this point and for a dormer conversion, the dormer will be constructed.

• Week 3 - External Finishing and Insulation

  Any external work will be finished during this week, including construction within the roof area and if any tiles need replacing or fitting. 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 - Windows and Flooring

  Windows not yet installed can now be fitted, the floor laid, including any ventilation as needed. The plasterboard will be installed, and any internal walls built.

• Week 5 - Staircase and Bathroom

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

• Week 6 - Finishing Touches and Clean-Up

  Any unfinished jobs will be completed during this week and if your contractor is responsible for decorating, this will be included as part of the finishing touches. Scaffolding can then be removed and the last of the waste taken away.

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 creates 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.

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 can increase the value of a property by up to 20%.

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.

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.

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, whereby 2.2m is generally considered enough to provide clear head room - although this may vary on the individual build.

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.

Can I Have a Loft Conversion in My Bungalow?

Yes, it's normally possible to get a loft conversion in a bungalow. 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.

But how much does a bungalow loft conversion cost?

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.

Benefits of a Loft Conversion

There are a wide number of benefits to adding a loft conversion to your property, some of which we've already touched on but there are others to also consider. Below is a summary of just a few reasons to consider the investment:

• Add Value To Your Home - The money that you put into can potentially increase the resale value of your property by up to 20%.
• Increase Your Living Space - Loft conversions are a great way of expanding your living area without the hassle of moving.
• Adding Natural Light - Installing windows during the conversion can bring additional natural light into your home.
• Energy Efficiency - Required insulation during conversion improves energy efficiency which can help reduce heating bills.
• Doesn't Impact Outdoor Areas - Unlike an extension or conservatory, a loft conversion doesn't encroach on your garden or driveway.

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 yourself 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 can potentially cost half as much that of a professional job, but could take much longer to complete. However, it also requires a lot of manual work and extensive knowledge, so it isn't generally recommended as a DIY project.

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.

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 £700-£1,500 with the higher-end reflecting London properties or more complex cases.

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.

Possible Issues You May Come Across When Converting a Loft

While planning in advance and hiring the right contractor for the job will eliminate many potential issues, there are times when you can become faced with unexpected hurdles. Some of these we've addressed below.

• 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.
• Finding Asbestos - In an older property, it is possible that you might come across asbestos in your loft space, this needs to be professionally removed by a qualified...
• Furniture That Doesn’t Fit - Your choice of staircase may limit access, resulting in not being able to fit in your desired furniture. This should be taken into consideration in advance.
• Incorrect Fixtures and Fittings - As well as the size of fixtures such as baths and showers, it's important to ensure utilities are fitted in the correct place, as well as allowing space for doors etc.
• Missing Planning Permission - To avoid costly fines or having to undo any work, always check with your local council in advance if you are unsure if permission is required.

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