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Last updated: 26 March 2024

Velux Loft Conversion Cost 2024: A Complete Guide

Velux loft conversion: A complete cost guide
  • A Velux conversion for a medium-sized loft of 30-40m2, with 3-4 Velux windows, costs between £20,000 – £30,000
  • This type of conversion is the least expensive option and requires less work than other types of conversions, like dormer or hip-to-gable, for the same size
  • Costs cover work such as reinforcing the floor, adding insulation, and installing Velux windows, which improve natural light and ventilation. These enhancements make the space more livable and energy-efficient, helping to reduce heating costs and boost your property’s energy performance certificate (EPC) rating. 
  • By converting your attic into a functional area, you’re increasing the usable square footage of your home and its overall market appeal. This could raise your home’s value to 20-25%, a significant margin that sometimes surpasses the project’s initial cost.

What makes Velux loft conversions especially appealing is their high return on investment. They offer immediate benefits by making your home more comfortable and provide long-term financial and environmental advantages. 

This guide provides detailed information on the costs of a Velux loft conversion project and covers factors that affect the total prices, helping you make a well-informed decision.

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How much does a Velux loft conversion cost?

In the UK, in 2024, a complete Velux loft conversion costs between £15,000 and £30,000. This cost ranges from a small to mid-size conversion space, but it increases if you work in a larger area. 

This average cost covers strengthening the existing floor, laying flooring, insulation, plaster boarding, installing stairs and Velux windows. 

Here’s a detailed breakdown of costs, based on the various loft sizes:

Small Velux loft conversion of 20m2 to 30m2

small velux loft conversion cost UK

For lofts of this size range, the cost with two Velux windows (78cm x98cm) would typically be between  £15,000 and £20,000. This basic cost range includes strengthening the floor, basic flooring, insulation, plaster boarding, and window and stair installation. 

Medium Velux conversion of 30m2 to 40m2

Medium velux loft conversion cost UK

The average cost for a medium-sized conversion generally ranges from £20,000 – £30,000 for a standard property size. This estimate typically covers the installation of  3-4 Velux windows, which may include smaller MK04 or MK08 (78cm x 98cm) sizes (78cm x 140cm). The estimated cost includes both labour and building materials. 

Large Velux conversion of 40m2 to 50m2+

Large velux loft conversion cost UK

The cost of large loft conversions ranges from £30,000 to £45,000 and above. This estimate covers installing 4-6 mixed Velux windows, labour, and building materials. Because of the larger space, additional windows, labour, and materials will be necessary.  

These approximate prices may vary based on location and professional fees. 

Always consult with your architect or structural engineer in your local area for more accurate prices based on the size of your property and the interior finishings. 

Still, Velux loft conversions remain the easiest and most affordable option for UK homeowners in 2024. They require fewer structural alterations and no permits (unless in a conservation area) with faster completion than other conversions, making them more cost-effective. 

While a dormer, for instance, can cost around £30,000 for the same size (20m2). Hip-to-gable and mansard conversions can cost over £40,000 because of their complex construction and the required structural changes.

Below, we’ve broken down the approximate costs for a basic 30m2 Velux loft conversion, with materials and labour expenses, to give you a clearer idea of what to expect from each project component. 

JobTotal avg. cost range(incl labour)
Velux windows installation – 2 standard £1,185 – £1,285
Reinforcing floor£4,750 – £6,000
Insulation £450 – £1,200
Electrical wiring££550 – £1,000
Staircase£1,000  – £1,500
Drywall and plaster boarding£750 – £2,000

These approximate costs are subject to change based on location, type of home, material cost, and labour and professional service cost. 

Velux loft conversion cost by type of window

Velux roof window types.

Now that we’ve discussed the estimated cost of a Velux loft conversion, we will focus on the prices of the windows by type with installation so you can budget accordingly. 

This table summarises the different Velux windows, their main features and estimated prices, including VAT, standard flashing and installation labour costs in the UK.

Window typesFeaturesCost with installation
Centre-PivotStandard operation£929 – £1324
Top-HungUnobstructed view£1,253 – £1,850 
Top-Hung w/ ThermoEnhanced insulation£1,300 – £2,000 
Integra Electric/SolarRemote operation£1434 – £2,250
Cabrio BalconyBalcony access£4,300 – £6,800*
Conservation For listed buildings£1,200 – £2,200
Prices include VAT

* If you need third-party scaffolding, the price can increase by £500 for installing Cabrio Balcony.

The cost also depends on the roof window size, with the standard size 78 × 118 cm to bigger modular 2n1 and 3n1 windows. 

Different Velux window options offer varied benefits, especially if you want to reduce heat loss in your home. 

If you want to enhance energy efficiency, consider energy-efficient Velux windows. These can lower heating costs and increase your home’s appeal to potential buyers, highlighting a commitment to sustainability and energy savings. 

According to GOV.UK, improving your home’s energy efficiency is the quickest way to answer rising energy prices and reduce your heating bill by at least 20%. 

Energy-efficient windows can also improve your home’s Energy Performance Certificate (EPC) rating, an important aspect of the property market. Homes with better EPC ratings often sell faster and at higher prices.

So, if improving your home’s future value and marketability is a priority, energy-efficient Velux windows could be an option worth exploring.

What affects the costs of your Velux loft conversion?

Various factors can influence the total cost of your conversion, such as the location, the size of your loft, the complexity of your project, and the finishes you choose.

In this section, we’ll walk you through all the factors you need to know. 

Your location: Where you live can affect the cost of your Velux loft conversion. For instance, 

  • If you live in London, you can expect to pay around £40,000 to £48,000, including VAT, according to Scott McCabe Associates. That is because of higher labour costs, materials, and finishings. 
  • However, if you live in Durham, the average cost is much lower, ranging from £15,000 to £20,000, according to NationalLoftConversions.
Measuring roof space.

Loft size and roof space: The dimensions of the loft and the condition of the existing roof space directly influence the amount of work required. 

Larger areas require more materials and extended labour. Also, to ensure the space is well-lit and ventilated, you may require additional or bigger Velux windows, which increases the price. 

In addition, adding a kitchen or bathroom could increase the project’s cost by £6,000 and £10,000, according to MyJobQuote. The materials used also increase in price.

Number and types of windows: The number and specific types of Velux windows selected for converting your space to a loft affect the overall cost. For instance, 

  • Velux windows with energy-efficient glazing or electric opening mechanisms can enhance the functionality of a loft space while reducing energy use and bills.
  • Although such windows may cost more upfront, they offer long-term benefits, making them a wise investment for a sustainable and comfortable living environment.
  • Affordable window options are also available to meet specific needs and budget constraints.

Structural work: If significant alterations, such as reinforcing the floor or changing the roof structure, are necessary to comply with building regulations, the project will become more complex and expensive.

Design and finishes:

Your Velux loft conversion cost will depend on your chosen design and finishes. Basic designs cost less, while custom designs with high-end finishes can significantly increase the budget. The level of interior finishing, which ranges from basic to luxury, also affects the ultimate cost and depends on the materials and labour involved. Ultimately, the cost will depend on your budget and aesthetic choices. 

Additional expenses you can expect

Besides the essential elements of a Velux loft conversion, extra costs may arise depending on the details of your project. These additional expenses can include things like structural engineering, which we will cover. The property’s location usually determines such expenses, the existing loft’s condition, and your preferences for style and design.

Scaffolding (Optional): If you want to change your roof structure, you may need to add more support. However, if you only want to install small to medium-sized Velux windows, you can do this from the inside of your house with no need for a scaffold.

You will need a scaffold to install bigger or more complex windows. The cost for the scaffolding job can range from £100 to £200 or £22.50 per m2 per day and may take 2 to 4 weeks, depending on the complexity of the work.

Skip rental: A skip is necessary for disposing of construction waste, such as old roofing materials and plaster. The most popular size is 6 yards, and it usually costs between £200 and £400 for a standard rental period of 14 days. 

Keep in mind that you’ll need to get skip permits from your local council. If you don’t get a permit, you could be fined. If you don’t properly mark the skip with safety lights and signage, you could face a fine of up to £1,000.

Professional services and their costs


Structural engineering: A structural engineer might need to assess the loft’s existing structure to ensure it can support the conversion, including any additional weight from new windows or internal finishes. It is crucial when planning any necessary reinforcements or alterations. 

Architect (optional): An architect can help you convert your loft into a functional and visually appealing space. They can help choose Velux windows, which are often exempt from planning permission. 

They’re also up to date with building regulations and will‌ help you navigate and meet the requirements. 

If you live in a conservation area, they can help you with designs that align with the strict rules for structural changes, even for installing Velux windows. An architect can also assist with specific ideas or a unique design for your loft. 

The minimum fee starts at about £500 and increases to £2,000 at the higher end. This could be for professional advice on material choices, designs and layouts that fit your needs while adhering to building regulations. 

Costs of additional features

Adding more features to your Velux windows can make a room more convenient and functional.

Although these features may increase the starting cost, they can lead to long-term savings and comfort. 

From energy-efficient blinds to smart remote controls, each feature makes your living environment more adaptable to your needs while also considering the environment.

Here are additional Velux window features that can enhance the sustainability and usability of your loft conversion:

FeatureBenefitsCost range per window
Solar-Powered BlindsOptimise natural light£80 – £500
Remote-Controlled WindowsImproves ventilation £100 -£300
Integrated Rain SensorsPrevents water damages£30 – £50
Energy-Efficient WindowsReduces heat loss£250 – £900
Low-VOC Paints and FinishesEnhance air quality£400 +

These are estimated prices and can change anytime. 

Despite the additional expenses involved, a Velux loft conversion costs only a fraction of the price of other types. It’s still the easiest and most affordable option to transform your attic into a functional living space.

Building regulations and permits costs

These requirements ensure your safety, compliance, and consideration for neighbours, but they can also increase your overall loft conversion cost in the UK. 

Let’s explore them:

  • Planning Permission: £200
  • Party Wall Fees: £800 to £1,500
  • Building Control Fees: £800 to £1000

Here is what they mean for you: 

Planning Permission: Most times, Velux loft conversions fall under the “Permitted Development” category, not requiring planning permission, according to the UK Planning Portal.

However, if your property is in a conservation area, is a listed building, or requires significant changes to the roofline, you may need planning permission. The cost to apply for planning permission is usually around £200, but this can vary depending on where you live and the local authority.

Party Wall Fees: If your loft conversion work affects a wall shared with neighbours (a party wall), you’ll need to comply with the Party Wall Act 1996. 

This involves notifying your neighbours of the work you intend to do and may require hiring a party wall surveyor to draft an agreement. 

The cost of hiring a surveyor for a party wall can vary based on the complexity of the agreement and whether two parties need surveyors. If you’re a homeowner, budget around £800 to £1,500 for party wall fees, according to Harding Chartered Surveyors.

This can be more expensive for mid-terraced homes because Party Wall agreements on both sides of the property are needed. 

Building Control Fees: All loft conversions must comply with building regulations to ensure the project meets health and safety standards. 

To achieve this, you must submit detailed plans and specifications to your local building control body, which will conduct inspections at various project stages. 

The cost of building control approval can vary depending on your project’s size and location, with costs usually ranging from £800 to £1000, according to Build Partner UK.

How much value does a Velux loft conversion add?

Added value of velux loft conversion.

A Velux loft conversion is not just a regular home improvement project. It is a valuable investment that can improve your property’s functionality, appearance, and even sustainability‌ and add significant value. Here’s how:

Increased living space: A Velux loft conversion can transform an uninhabitable attic into a functional living area, such as an extra bedroom, home office, or recreational space. This can maximise the usable square footage of your home and provide additional living space that is highly appealing to potential buyers. This can make your property stand out, potentially increasing its value.

Increased marketability: Adding high-quality Velux windows to a well-executed loft conversion can enhance its beauty and offer natural light and ventilation, which home buyers highly value. This functional and beautifully designed space can substantially increase the market value of your property.

Some Velux windows, like the Top-Hung Roof Windows with ThermoTechnology, enhance energy efficiency. These windows are insulated to prevent heat loss, which can help you save on heating costs. According to Investec, energy-efficient homes can increase property value by 19.6%, making them more attractive for marketability based on a higher EPC.  Although energy-saving windows might cost more initially, they can save you money in the long run, improve your comfort and add value to your property.

High return on investment (ROI): Loft conversions offer one of the highest ROIs among home improvement projects. A Velux loft conversion, in particular, can add more living space and square footage to your home, increasing your home’s overall value by 20-25%. According to Abbey Loft, this increase can sometimes surpass the project’s initial cost if you decide to sell. Plus, compared to other types of loft conversions, such as a dormer, a Velux conversion is the most affordable option, making the ROI particularly appealing.

Choosing a Velux loft conversion is a strategic investment to enhance your property’s functionality, aesthetic appeal, and sustainability. It expands living space, making your home more attractive to potential buyers, and can boost property value further by making it energy-efficient. With a high ROI, this affordable conversion option provides immediate benefits and long-term enhancement.  

At GreenMatch, we strive to empower you to make informed decisions. That’s why we offer four free loft conversion quotes: to help you save time and money and gain confidence in finding the best suppliers for your loft conversation project.


Rousanna Baird
Written by Rousanna Baird, External Writer

Rousanna is an SEO content writer at Household Quotes with a background in digital marketing and copywriting. She creates informative, well-researched home improvement content based on practical ideas to help readers make informed decisions.

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