How Much Does A Loft Conversion Cost: Complete Guide For 2025

Loft conversions are a popular way to add space and value to your home in London. But how much does a loft conversion cost in 2025? This guide provides a detailed breakdown, helping you understand the costs, factors that affect pricing, and how to get an accurate quote.

Whether you’re considering a dormer, or a mansard, or some other type, we’ve got you covered. Wish to speak to a local loft conversion specialist for tailored solutions and accurate pricing? Feel free to reach out to us today – call 01732 523199.

The Average Cost Of A Loft Conversion In 2025

Loft conversion costs vary depending on the type and complexity of the project.

Here’s a cost breakdown based on various loft conversion types in 2025:

1. Velux Loft Conversion – From £35,000 To £50,000.

Velux conversions are the most cost-effective option, as they involve installing skylight windows without altering the roof structure. They are suitable for homes with ample existing roof height and are quicker to complete compared to structural conversions.

2. Dormer Loft Conversion: From £45,000 To £60,000.

A dormer extends vertically from the roof slope, creating additional floor space and headroom. It’s a versatile option that accommodates various room types, from bedrooms to home offices, and is popular for its balance of cost and functionality.

3. Hip-To-Gable Loft Conversion: From £55,000 To £75,000.

This type of conversion replaces the sloping side of a roof with a vertical wall, increasing internal space. It’s ideal for semi-detached or end-of-terrace properties and blends seamlessly with the home’s exterior design.

4. L-Shaped Loft Conversion: From £70,000 To £90,000.

L-shaped conversions combine two dormers to form an L shape. They are perfect for creating multiple rooms, such as a master bedroom with an en-suite. These conversions are best suited for period properties with existing rear extensions.

5. Mansard Loft Conversion: From £75,000 To £100,000.

Mansard conversions involve extensive structural work, replacing one side of the roof with a nearly vertical wall and a flat roof. They offer the largest increase in living space and are ideal for adding luxury features but come with higher costs and longer completion times.

These figures include insulation, ventilation, and compliance with building regulations. However, additional costs may apply for finishing touches like bespoke fittings or luxury materials.

Which Factors Affect Loft Conversion Costs?

Several factors influence the cost of a loft conversion. Understanding these can help you budget effectively in 2025:

1. Size Of The Loft

The larger the loft, the higher the cost. A bigger space requires more materials, labour, and time, increasing the overall price. The complexity of the conversion also grows with the size of the area.

2. Type Of Conversion

There are various types, such as dormer, mansard, or velux. Dormer conversions, for example, are typically more expensive than Velux ones due to the structural changes required. The design complexity directly impacts costs.

3. Building Regulations & Planning Permissions

Complying with building regulations and acquiring planning permission can add to the cost. Certain types of loft conversions require official approval, which involves fees and additional time for inspections, potentially delaying the project and increasing overall expenditure.

4. Structural Work

If the loft requires significant structural modifications like strengthening the floor or adding new supports, costs will rise. The complexity of these changes, including potential reinforcement of the roof, can significantly impact the overall price of the project.

5. Roof Structure

The condition and type of the existing roof affect the cost. A pitched roof may need additional work, while a flat roof could require insulation or repairs. The existing structure’s suitability for conversion plays a crucial role in pricing.

6. Materials Used

The quality of materials chosen will influence the cost. High-end materials, such as premium insulation, luxury flooring, and custom windows, raise the price compared to standard options. However, material selection is crucial, as it directly contributes to both appearance and energy efficiency.

7. Labour Costs

Labour charges vary by region, contractor experience, and the complexity of the job. Hiring skilled tradespeople, such as architects and structural engineers, often leads to higher labour costs but ensures high-quality results and compliance with regulations.

Worry not – at Bigger Living Lofts, we strive to ensure the most reasonable loft conversion pricing tailored to your requirements and budget constraints.

8. Location

The geographical location of the property significantly impacts the cost of a loft conversion. Loft conversions in metropolitan areas tend to be more expensive due to higher labour rates, increased demand, and the cost of living in the area.

9. Additional Features

Including extra features like en-suite bathrooms, dormer windows, or custom-built storage spaces can add to the overall cost. Each added feature requires additional materials, design time, and skilled labour, thus increasing the total project price.

10. Access To The Loft

The ease of access to the loft space influences the cost. If the space is difficult to reach or has limited access for workers and materials, additional costs for scaffolding, machinery, and manual labour may arise.

Get An Online Estimate From Bigger Living Lofts Today!

At Bigger Living Lofts, we combine over 30 years of expertise with a tailored approach to meet your unique loft conversion needs. As a family-run business, we prioritise safety and quality at every stage of the project. Our team ensures every loft conversion complies with regulations and exceeds your expectations, creating a functional and beautiful space for your home.

We begin with a comprehensive survey conducted by our experienced surveyor, who will visit your property to assess your requirements. Based on this, we provide a free, detailed quotation that outlines all costs and the scope of work. This transparent approach ensures there are no surprises and allows you to make informed decisions with confidence.

Once the quotation is approved, our dedicated team handles the entire process, from initial design to final completion. Whether you’re adding a bedroom, office, or living space, we’ll deliver a bespoke solution tailored to your vision.

Contact us today on 01732 523199 to start your journey toward a stunning loft conversion.

Guess what – we can also offer you an online estimate if you take only a few minutes to complete this quick form on our website. We’d still encourage you to contact us directly for an accurate quotation.