Get Double Space with a Mansard Loft Conversion

Key Takeaways

• Mansard loft conversions create a near-full extra storey, perfect for bedrooms, offices, or multi-room layouts.
• Adds significant value to terraced, semi-detached, or detached homes. 
• Typically £50,000–£60,000 depending on size, design, and location.
• Usually requires planning permission and may need a party wall agreement.
• Options include L-shaped, double mansard, ensuites, open-plan spaces, and smart storage solutions. 

If you are a homeowner in the UK, you have either planned or are planning to create some space in your attic or loft. Since you have moved or purchased the property, this thing is on your to-do list, and now with the extended family needs, you have to do it anyhow.

Many of the homes in the UK have undergone renovations, either by loft conversion or extension, and our topic for the blog, Mansard Loft Conversion, is outshining the most.

If we look at some recent data that shows how many loft conversions were done last year, then you will not be surprised.

“According to 2025 surveys published on Nationwide, around 24% of homeowners undertaking major renovations choose loft conversions, reflecting their appeal in urban areas where space is at a premium.”

In this article, we will let you know every little detail that you should know before constructing a Mansard loft, and if you have already done it, you can improve it as well. Let’s get started!

So, What is a Mansard Loft Conversion Exactly?

A Mansard loft conversion is just like making double the space in the loft than any other loft conversion. It’s more like making a whole separate floor in the attic. Which can be converted into any room or space of your choice.

Unlike a conventional loft conversion, a Mansard involves reshaping the roof to a vertical back wall at 72 degrees approx. Usually constructed at the backside of the house, this style makes the most of the available space. Windows are frequently set into box-like dormers, which allows natural light and gives a warm, inviting look that is compatible with the style of your home.

What are the Benefits of a Mansard Loft Conversion?

Mansard Loft Conversion is one of the most space-giving conversions you can have. As it transforms the shape of the entire roof to build either a bedroom, a bathroom or a home office:

Get Optimum Space: You can get more space, as this loft conversion can reshape the entire roof space and make it bigger and more spacious.

Add Aesthetics to Your Space: Designed to complement your home’s existing architecture, as you have a big bedroom and a luxurious safe. 

Value Addition: The mansard loft conversion definitely adds so much value to the overall property by making a luxurious bedroom, bathroom, or home office. 

Versatility: This type of loft conversion is suitable for a variety of homes. Works with terraced, semi-terraced, semi-detached, detached, and even listed buildings.

Best Design Options for a Mansard Loft Conversion 

One of the biggest advantages of a mansard loft conversion is the freedom it gives you when it comes to design. Because it creates a near full-height extra storey. You’re not limited by awkward slopes or tight corners.

Here are some of the most popular and practical design options homeowners choose:

Master Bedroom with en-suite 

This is by far the most common choice. A mansard conversion easily accommodates a spacious master bedroom with an ensuite bathroom and built-in wardrobes. It’s perfect for growing families or homeowners who want a private retreat away from the main living areas.

Guest Bedroom or Rental Space  

With generous head height and natural light from dormer windows, a mansard loft works brilliantly as a guest bedroom. In cities like London, many homeowners also design the space as a rental room or studio to generate extra income. 

Home Office or Creative studio

As remote work becomes more common, turning your mansard loft into a home office or studio is a smart move. The separation from the rest of the house creates a quiet, focused environment while still making use of previously unused space. 

Children’s Bedroom or Playroom 

A mansard loft conversion is ideal for creating a bright, spacious bedroom for children or a dedicated playroom. Clever storage solutions, such as built-in cupboards under dormer windows, help keep the space organised and clutter-free.

Open-plan Living Space

Some homeowners choose to create an open plan lounge, reading room, or entertainment space. With the extra floor area a mansard provides, you can add comfortable seating, shelving, and a small kitchenette if required. 

Do You Need Planning Permission for a Mansard Loft Conversion?

Yes, a Mansard loft conversion changes the roof structure quite visibly. Planning permission to build is generally needed, particularly in conservation areas or for listed buildings. If you live in a terraced or semi-detached house, a party wall agreement may be required too to keep neighbours satisfied and the process running smoothly.

How Much Does a Mansard Conversion Cost?

The cost of a Mansard loft conversion is usually more than other types because of its size and degree of difficulty. The average cost for a mansard loft conversion in London is between £50,000 and £60,000; this depends on the size of the property, the materials used and whether or not there is any party wall work involved.

You Can Also Read More: Dormer Loft Conversion

Key Differences Between Dormer and Mansard Loft Conversions

What is an L-shaped and double mansard roof loft conversion?

L-shaped Mansard:

This expands the loft conversion across the width of the house, usually above the kitchen or side extension, providing also more rooms and storage.

Double Mansard:

This has a front and rear mansard, effectively giving you a new storey, perfect for period or large London houses.

Which Houses Are Suitable for a Mansard Loft Conversion?

Mansard conversions are suitable for a variety of houses: Mainly these include Terraced which have the rooftop built like classic Victorian or Edwardian ones, and often work well. It also works efficiently for semi-detached homes, which have ample space at the rear that allows vertical expansion.

Lastly, detached homes offer full design freedom and maximum space. Even listed buildings and homes in conservation areas can have mansard conversions with careful planning.