Are you considering a loft conversion but unsure of the costs involved? Look no further! In this article, you’ll find a breakdown of the loft conversion cost for different types of loft conversions, as well as how long the job will take and a general overview of what the job entails.
On average, a loft conversion will cost between £40,000 £80,000 and take about 6-9 weeks to complete. However, the cost can vary depending on the type of conversion, finishes, and house type. By splitting up the costs of different loft conversions, this article aims to provide a quick and easy way to get a ball-park figure in mind before hiring a conversion specialist, hopefully saving readers from getting ripped off.
Whether it be a small loft conversion or a dormer with an ensuite, this article can help calculate the costs for you. So, if you’re ready to get a quote for your loft conversion, read on!

How Much Does A Loft Conversion Cost?
The cost of a loft conversion project varies depending on the type of conversion chosen. The most affordable option is a Velux loft conversion, which can cost between £15,000-£20,000 on average. A dormer loft conversion, which involves extending the roof with a dormer window, is more expensive, with costs ranging from £30,000-£60,000.
A hip-to-gable conversion, which changes the shape of the roof, will cost between £40,000-£65,000. The most expensive option is a Mansard loft conversion, which involves changing the entire shape of the roof and can cost between £45,000-£70,000.
It is important to note that the final cost of a loft conversion project will depend on the size of the conversion and the level of finish desired. The bigger the size and the higher the quality of the finish, the higher up the price bracket the conversion will be.
When planning a loft conversion project, it is crucial to set a budget and make informed decisions to balance the final result with the cost. Homeowners can use a cost calculator to estimate the cost of their loft conversion project and plan accordingly.
Loft Conversion Prices
When considering a loft conversion, the cost is a significant factor to consider. The cost of a loft conversion can vary depending on several factors, including the size of the conversion and the type of conversion.
Cost by size of loft conversion
The size of the conversion is one of the most significant factors that affect the cost of a loft conversion. The table below shows the average cost of a loft conversion based on the size of the loft room.
Size (m) | Average Cost |
---|---|
5 x 4 | £20,000-£35,000 |
5 x 6 | £35,000-£55,000 |
8 x 12 | £45,000-£75,000 |
Cost by type of loft conversion
The type of conversion is another factor that affects the cost of a loft conversion. The table below shows the average cost of a loft conversion based on the type of conversion.
Type of Conversion | Average cost |
---|---|
Velux Loft Conversion | £15,000-£25,000 |
Dormer Loft Conversion | £30,000-£60,000 |
Hip-to-Gable Loft Conversion | £40,000-£65,000 |
Mansard Loft Conversion | £45,000-£70,000 |
Example Loft Conversion Cost Breakdown
There are several jobs involved in a loft conversion, and the cost breakdown can help give an idea of what to expect. The table below shows an example cost breakdown for a £45,000 conversion, which includes putting in about 30m2 of loft space, a dormer, and a roof light over the new staircase. This includes the electrics and plumbing for a master bedroom with an ensuite.
Job | Cost for 30m2 loft |
---|---|
Project Management – including building control costs | £9,000 |
Scaffolding | £4,000 |
Internal Preparation | £3,000 |
Alterations to Roof Structure | £5,000 |
Steelwork to support structural changes | £4,000 |
Roofing Covering | £6,000 |
Electrics | £1,500 |
Joinery – excluding staircase | £4,500 |
Staircase | £3,000 |
Plastering | £2,500 |
Decoration | £2,500 |
Total | £45,000 |
Overall, the cost of a loft conversion can vary significantly depending on the size and type of conversion. It is essential to consider all the factors involved before deciding on the type and size of the loft conversion.
Labour Costs and Timescales
General Labour Costs and Timescales Based On Conversion Type
The duration and cost of a loft conversion can vary depending on the type of conversion. For a Velux loft conversion, the average duration is 4-6 weeks, and the cost ranges from £8,000-£15,000. A dormer loft conversion takes 6-8 weeks and costs between £25,000-£45,000. A hip-to-gable loft conversion takes 6-8 weeks and costs between £25,000-£40,000. For a Mansard loft conversion, the duration is 8-10 weeks, and the cost ranges from £30,000-£50,000.
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. On average, 2-3 tradespeople will be on-site at all times.
Cost Per Hour of Different Tradespeople
It’s important to note that the costs per hour can vary depending on the location and experience of the tradesperson. It’s recommended to obtain multiple quotes from different tradespeople before making a decision.
When planning a loft conversion, it’s important to factor in the cost of labour and the duration of the project. Understanding the general costs and timescales for different types of loft conversions and tradespeople can help with budgeting and scheduling.
Supply Costs
Loft Conversion Windows
There are two types of loft conversion windows that are commonly used – Velux and Dormer. The average cost of Velux windows ranges from £350 to £750, depending on the size. The average cost of Dormer windows ranges from £300 to £800, depending on the size.
Loft Conversion Flooring
When it comes to loft conversion flooring, there are several options to choose from. Vinyl flooring is the cheapest option, with an average cost of £20-£40 per m2. Wood flooring is more expensive, with an average cost of £20-£80 per m2. Carpet and tile flooring are also options, with average costs ranging from £15-£50 per m2, respectively.
Loft Conversion Insulation
Insulation is an important factor to consider when converting a loft. The average cost of sheet insulation is between £20-£40 per m2. Loose-fill insulation is cheaper, with an average cost of £10-£30 per m2. Blanket insulation is the most expensive option.
Loft Conversion Stairs
Stairs are an essential part of a loft conversion. Basic stairs can cost between £1,500-£3,000. Custom oak staircases can cost between £5,000-£20,000. Spiral stairs are a cheaper option, with an average cost of £1,000-£2,500.
General Building Materials
There are several general building materials that are required when converting a loft. The cost of electrics ranges from £500-£1,000. The cost of structural beams, joists, and masonry ranges from £2,500-£5,000. The cost of a bathroom ranges from £3,500-£7,500. Decorating materials cost between £800-£2,000. Built-in storage, like bespoke furniture, can cost between £1,500-£10,000.
It is important to note that the costs listed above are only estimates and can vary depending on several factors such as location, quality of materials, and complexity of design.
Additional Costs
When building a loft conversion, there are several additional costs that may arise. These costs include plans drawn up by architects, which can range from £500 to £2,500. House exterior repainting can cost between £500 and £2,500, while house cladding can cost between £2,000 and £7,000. House render can cost between £2,000 and £8,000.
Replacing roof tiles can cost between £150 to £500. Bat surveys can cost between £300 and £600, while building regulations can cost between £100 and £500.
Party wall surveys can cost between £150 and £350, and moving a water tank can cost between £150 and £250. A new boiler can cost between £1500 and £3500. It is important to note that the cost of these additional expenses may vary depending on factors such as location, VAT, and conservation area regulations.
Cost Factors of a Loft Conversion

When planning a loft conversion, several factors can affect the cost of the project. The cost of a loft conversion varies depending on the type of conversion, the size of the loft, and the complexity of the project. In this section, we will discuss the cost factors of a loft conversion.
Type of Loft Conversion
There are four main types of loft conversions: Velux, Dormer, Hip-to-Gable, and Mansard. The type of conversion you choose will affect the cost of the project.
- Velux Loft Conversion Cost: This is the cheapest type of conversion. It involves adding windows to the existing roofline without changing the shape of the roof. The cost of a Velux loft conversion can range from £15,000-£25,000.
- Dormer Loft Conversion Cost: This type of conversion involves extending the roofline to create extra headspace. The average cost for this type of conversion is £30,000-£60,000.
- Hip-to-Gable Loft Conversion Cost: This type of conversion involves changing the shape of the roof. The average cost for this type of conversion is £40,000-£65,000.
- Mansard Loft Conversion Cost: This is the most expensive type of conversion. It involves changing the entire shape of the roof and adding dormer windows. The average cost for this type of conversion is £45,000-£75,000.
Size of Loft Conversion
The size of the loft conversion is another important factor that affects the cost of the project. The more alterations, the higher the cost of the project. For example, creating a large master bedroom with an ensuite and built in wardrobe, would involve moving plumbing and electrics so the space is suitable for a new bathroom.
Window Choices
The number and type of windows can also impact the cost of a loft conversion. Dormer windows are more expensive than Velux-style windows.
Internal Walls
Adding internal walls to the loft space will increase the cost of the project. To put in a stud wall and plaster it will cost around £800 to £1500.
Plumbing Cost
The cost of plumbing will depend on the amount of plumbing required. The cost of materials and the plumber’s time will also affect the cost.
Electrical Cost
The cost of electrical work will depend on the number of electrical sockets and lights required. In conclusion, the cost of a loft conversion depends on several factors such as the type of conversion, size of the loft, and complexity of the project. Homeowners should carefully consider these factors before embarking on a loft conversion project.
What’s Involved in a Loft Conversion?
A loft conversion is a significant undertaking that involves various steps. The process can take around six to ten weeks to complete, depending on factors such as the size and complexity of the project. Here are the steps involved in a typical loft conversion:
Week 1
The first stage is to erect the scaffolding, which will provide access to the roof. The materials needed for the job will be gathered on-site, and the roof will be opened up during this week. The structural work, such as reinforcing the roof structure, will also take place during this week.
Week 2
If the roof structure is changing, extra supports may be installed if needed. For a roof light conversion, the windows will be installed now. For a dormer conversion, the dormer will be constructed. This week will also involve finishing any structural work.
Week 3
During this week, the external work will be completed. 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 yet been fitted will be installed during this week. The floor will be laid with any necessary ventilation. The plasterboard will be fitted, and any internal walls will be built.
Week 5
The staircase will be installed at this point. If a bathroom is being added, it can be fitted at the same time. The electrics will also be finished during this week. Towards the end of the week, the doors will be hung, the plaster skimmed, and the skirting fixed.
Week 6
During this final week, any unfinished jobs will be completed. If the contractor is responsible for decorating, that will happen during this week. The scaffolding will also come down during this week.
It is worth noting that this is an ideal schedule, and the actual duration of each step may vary depending on the size and complexity of the project. The process can also be affected by factors such as the weather and any unforeseen issues that may arise during the construction process.
Do I Need an Architect for a Loft Conversion?
Whether or not an architect is needed for a loft conversion depends on the contractor chosen. Some loft conversion specialists are willing to work without an architect and rely on their own experience, which can save money early on. However, this approach may lead to problems later on.
Drawing up plans with an architect serves two primary purposes. Firstly, it ensures that the work can be completed safely. Secondly, it provides a clear and agreed-upon vision for what the final product will look like. Without plans, there is a risk that the contractor and client will work at cross purposes. With a set of plans, a record of what is expected from the final project is available.
The cost of getting plans drawn up depends on their level of detail. Basic plans typically cost around £500, while more detailed plans can cost up to £1,500. The more detailed plans can be helpful in allowing contractors to give an accurate loft conversion price guide.
While an architect is not always required for a loft conversion, it is recommended to ensure safety and clarity of vision. Basic plans can be relatively affordable, and more detailed plans can be helpful in providing an accurate price guide.
Loft Conversion Ideas
If you’re considering a loft conversion, you have a lot of options for how to use the space. The possibilities are endless, but here are some common ideas to get you started.
Children’s Bedrooms
Loft conversions are a popular choice for children’s bedrooms. The space can feel like a fun hideaway for kids, and the sloping ceilings can add character. If the room is narrow, a child’s bed might work better than a full-sized one.
Master Bedroom with Ensuite

A loft room can make for a luxurious master bedroom. The sloping ceilings can create a cosy atmosphere, and an ensuite can make the space feel like a private retreat.
Guest Room
A loft conversion can be a great place for a guest room. Since it’s not used every day, it’s easy to close it up when it’s not in use. Plus, your guests will appreciate having their own special space in your home.
Playroom
For families with young children, a loft room dedicated to toys can be a blessing. The sloping ceiling can make for exciting hiding places and forts, and your kids’ imaginations can run wild.
Office
A loft room can make for a quiet and private office space. Since it’s tucked away at the top of the house, you’re less likely to be interrupted. It can also create a separation between work and home life.
Bathroom
While bathrooms are often viewed as purely functional spaces, a loft conversion can give you the opportunity to create a decadent spa room. With a blank canvas to work with, you can design a bathroom that feels luxurious and indulgent.
Home Cinema
The cosy dimensions of a loft room can make it a perfect spot for a home cinema. Going up the stairs to watch a film can make it feel like a special experience, and the sloping ceiling can create a cosy atmosphere.
Overall, the intended use of your loft conversion will depend on your needs and preferences. With a little creativity, you can turn your loft into a space that’s both functional and beautiful.
Do You Need Planning Permission for a Loft Conversion?
Homeowners who are considering a loft conversion may wonder whether planning permission is required. The good news is that some loft conversions can be carried out under permitted development rights, without the need for planning permission.
Permitted development rights allow for certain types of development to be carried out without the need for planning permission, subject to certain limits and conditions. For loft conversions, the following conditions must be met:
- The loft conversion cannot extend beyond the existing roof
- The loft conversion cannot be higher than the highest part of the existing roof
- The loft conversion must be similar in appearance with no verandas, balconies or raised platforms
However, there are other rules and considerations that need to be taken into account. Homeowners should consult an architect or loft conversion specialist for more information on the permitted development rules. It is also important to check with the local planning department before making any changes to ensure that the loft conversion falls within the permitted development rights.
If the loft conversion does not fall within the permitted development rules, planning permission will be required. Homeowners can submit an application for planning permission online, but there will usually be an application fee that must be paid, which will be a minimum of around £200 to £400.
Building Regulations for Loft Conversions
Any loft conversion in the UK needs to meet building regulations, regardless of whether planning permission is required or not. The purpose of building regulations is to ensure that the new rooms are safe, structurally sound, and meet certain standards. This is important for the safety of anyone who will be using the space.
Building regulations approval 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. The regulations cover various aspects of the conversion, including fire safety, insulation, ventilation, and access.
It is the responsibility of the homeowner to ensure that all the work meets building regulations. 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, it is important to check with your builder that they will do this.
Failure to comply with building regulations can result in fines, legal action, or even the removal of the loft conversion. Therefore, it is crucial to obtain building regulations approval before starting any work on a loft conversion.
Party Wall Agreement
If your loft conversion affects the party wall, you are required to inform your neighbour. This could be the case if you plan to remove a chimney that sits against the party wall during your loft conversion. If you are unsure, you can hire a party wall surveyor to provide guidance, which typically costs between £200-£500.
If you need an agreement, you must notify your neighbour at least 2 months before work starts but no more than 1 year. It is advisable to speak to your neighbour about it first. Once you have notified them of the work, they have two options: they can either agree to the work or dissent.
If your neighbour dissents, you will need to get an agreement drawn up. This usually costs between £800-£1,500. The party wall agreement documents the condition of the party wall and sets out conditions identifying responsibility for any damage to the party wall.
In many cases, it is possible to save money by simply talking to your neighbour and coming to an amicable agreement. In this case, it is important to document the state of the party wall before commencing work.
In summary, if your loft conversion affects the party wall, you must notify your neighbour and obtain a party wall agreement if necessary. It is advisable to speak to your neighbour about the work and try to come to an agreement to save costs.
Benefits of a Loft Conversion
A loft conversion is a great way to add value to your home while also providing additional space. Here are some of the benefits of adding a loft conversion:
Add Value To Your House
A loft conversion is one of the best ways to add value to your home. It is an investment that will pay off in the long run. According to Checkatrade, a typical UK loft conversion will cost around £50,000. However, this price tag can vary considerably depending on the size and complexity of the project. 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.
Avoid the Cost of Moving
If you are outgrowing your current home, then your only options are to move or extend your home. A loft conversion offers you a way to get more space without the cost and hassle of moving. This can save you a lot of money and time in the long run. As per Roof Advisor, converting your loft costs a lot less than building an extension or moving to another home.
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. This is a great way to add more natural light to your home without having to install additional lighting fixtures. According to Which?, loft conversions can be a cost-effective way to add value and living space to 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. This is a great way to save money on your energy bills while also reducing your carbon footprint.
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 conversion, you gain more space in your home without sacrificing your garden. This is a perfect choice for a growing family. According to Homebuilding, loft conversion costs will depend upon a multitude of factors, such as size, location, complexity of design, and the type of loft conversion and desired quality of the internal fittings and finishes.
Will a Loft Conversion Increase My House Value?
A loft conversion is a popular home improvement option that can increase the value of a property. In fact, it is considered the best value for money option in terms of home improvement. On average, a loft conversion can increase the value of a property by 15-25%.
However, before starting the conversion, it is important to research the ceiling of house prices in your area. For example, if houses in your area sell for a maximum of £350,000, and you spent £320,000 on your home, then it is not worth spending more than £30,000 on your loft conversion, as spending more than that will not increase the value of your home further.
Therefore, it is recommended to fix a budget and do some research before starting a loft conversion to ensure that it adds value to your property without overspending.
Different Loft Conversion Options
There are four main types of loft conversion available in the UK. The type of loft conversion you choose will depend on how much loft space you have to start with and how much you are willing to spend. Here are the costs and pros and cons of each type of loft conversion.
Roof Light Conversion Cost
The simplest type of loft conversion is the roof light conversion. No changes are made to the shape of the roof. Windows are just added to let light in. This type of conversion is the cheapest option, with an average cost of £20,000-£30,000. It is also the least disruptive option. However, it is only possible if there is already a lot of headroom.
Pros
- Cheapest option
- Least disruptive
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. This type of conversion creates more space and is suitable for any home. 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 in a hip-to-gable conversion. The sloping roof at the side of the house is made vertical. This type of conversion creates lots more space. However, it is a big project and much more expensive than the previous two options. 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 in a mansard conversion. The new walls are steeply sloped up at around 720. This type of conversion gives the most space possible. However, it is the most expensive option and may require planning permission. The average cost for this type of conversion is £45,000-£70,000.
Pros
- Gives the most space possible
Cons
- Most expensive option
- May require planning permission
In summary, roof light conversions are the least expensive and least disruptive option, but only possible if there is already a lot of headroom. Dormer conversions are suitable for any home and create more space, but are more expensive. Hip-to-gable conversions create lots more space, but are a big project and much more expensive. Mansard conversions give the most space possible, but are the most expensive option and may require planning permission.
Can I Have a Loft Conversion in My Bungalow?
Yes, loft conversions are possible in bungalows. However, the type of conversion you choose will depend on the amount of headspace available in the loft. If there is enough headspace, a simple roof light conversion can be done. Otherwise, a dormer or a hip-to-gable conversion can be chosen.
The costs of loft conversion for bungalows are similar to those of two-storey houses. On average, a loft conversion for a bungalow can cost anywhere between £15,000 to £65,000 depending on the type of conversion chosen.
How to Keep Down Costs of a Loft Conversion
If you are looking to convert your loft, it is important to consider how to keep the costs down. Here are some tips to help you budget effectively and keep the project cost-effective.
DIY Parts Of The Job
Taking on some of the jobs yourself can also help cut costs. Even just doing the decorating can save you as much as £2,000. However, it is important to be realistic about your abilities and only take on tasks that you are confident you can complete to a high standard.
Plan Well
Planning is key to keeping costs down during a loft conversion. The highest costs often arise when decisions are made midway through the project. To avoid this, it is recommended to plan out everything you want in great detail before you begin. Getting an architect to draw up detailed plans can help with this and save you money in the long run.
Fix Your Budget and Stick To It
It is important to decide how much you want to spend on your loft conversion and stick to it. This involves deciding where and how you want to spend your money before work begins. Being strict with your budget can help ensure that you don’t overspend on items. It is also important to factor in a contingency fund of around 10% of the overall budget to cover any unexpected costs.
By taking on project management, doing some of the work yourself, planning well, and sticking to a budget, you can keep the costs of your loft conversion down while still achieving the desired results.
Possible Issues You May Encounter When Converting a Loft
When converting a loft, there are several potential issues that can arise. Good planning can help prevent most of these common pitfalls. Here are some of the issues to look out for:
Party Wall Disagreements
One of the most common issues that can arise when converting a loft is a disagreement with your neighbour over the work. This can cause delays and legal expenses. To avoid this, it is essential 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 two months before you start work, but no more than a year early.
Finding Asbestos
If your home is older, there is a chance that asbestos might be present in your loft space. Finding asbestos unexpectedly can be a significant issue. To avoid this, it is crucial to get your home surveyed for asbestos before you begin any work.
Furniture That Doesn’t Fit
The choice of staircase can limit the size of furniture that can be placed in your loft. If you have a specific piece of furniture that is quite large, it is essential to 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
When sourcing fixtures like baths, showers, and sinks, it is possible to find that they do not fit in the room. It is crucial to start planning early and 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 for your loft conversion, it can be very expensive to solve, and you might even have to undo all the work. To avoid this, it is essential to speak to the local council if there is any chance you might need planning permission.
It is also important to consider other potential issues that may arise during the conversion process, such as disruption to your daily routine, potential bat surveys if bats are present in the area, water tanks, drainage, and protected species. By considering these factors and planning accordingly, you can help ensure a smooth and successful loft conversion.
Hiring a Loft Conversion Specialist Checklist
When hiring a contractor for a loft conversion project, it is important to take certain factors into consideration to ensure that you are making the right decision. Here is a checklist of things to look for when hiring a loft conversion specialist:
- Previous projects: A reputable contractor should be willing to show you around previous projects. It is recommended to speak to the owners of the projects to get an understanding of their experience with the contractor. Ideally, you should see both a recently completed job and one that was done some time ago to get an idea of the quality of work you can expect.
- References: Ask the contractor to provide a few references of their previous clients. If they are able to give you several names, it is usually a good sign. When speaking to the references, check what their relationship with the contractor was like.
- Cost breakdown: Ensure that the contractor is willing and able to give you a full breakdown of all the costs involved in the project. This will help to avoid any misunderstandings about the work to be done and the costs associated with it.
- Note-taking: A good sign is a contractor who takes notes when you discuss what you want doing. This indicates that they are attentive to your needs and that things are less likely to be forgotten about.
- Building control visits: Check who will be responsible for organizing building control visits. While most contractors will do this, ensure that it is clearly agreed upon as it is ultimately your responsibility.
- Expertise: It is important to ensure that the contractor you choose has the necessary expertise to carry out the project successfully. This may involve working with a structural engineer or other experts to ensure that all calculations and surveys are done correctly.
By following this checklist, you can ensure that you are hiring a reputable and trustworthy loft conversion company who can deliver the project to your satisfaction. Get in touch with the specialists at A-Spec Ltd for a free estimate.