Mansard Loft Conversions

If you’re seeking to super-size your loft space, a Mansard loft conversion is the largest loft renovation you can choose. With over three decades’ experience of building all types of Mansard conversions across London, here is our quick guide. 

What is a Mansard Loft Conversion?

A Mansard conversion is typically built to the rear of your property and has a horizontal roof with an almost vertical 72-degree back wall. This not only creates a vast amount of loft space but means it has desirable room shaped proportions.

Windows within a Mansard are usually housed within a box-shaped Dormer which project slightly, enhancing internal space even further and allowing natural light to flood in. Additionally, as the windows sit vertically facing outwards, the Mansard loft conversion looks as though it has always been part of your home.  

Mansard Loft Conversion

This slate clad Mansard loft conversion blends perfectly with the existing property.

Other types of Mansard loft conversion are:

  • L-shaped Mansard – This creates even more space than a rear Mansard as a further room is added to the back of the home, usually above the kitchen. 
  • Double Mansard – The largest loft conversion available, a double Mansard comprises a front and rear Mansard, essentially creating an entire new storey. Double Mansards are particularly suited to period London homes. We have carried out several double Mansard extensions, including the one below in Bow, East London.

This double Mansard on a Victorian home in Bow, East London created a spacious bedroom with bespoke built-in wardrobes and sizeable en suite. 

Take a 360-degree virtual tour of a Double Mansard loft conversion. 

Is my London home suitable for a Mansard loft conversion?

A Mansard is suitable for most house types in London, including modern and period terraced, semi-detached and detached homes. Mansards are also suitable for listed buildings and homes in London conservation areas providing they are built in accordance with local authority planning and regulation guidelines.     

We can advise you on planning and building regulation requirements you need to meet before starting your conversion.

What are the benefits of a Mansard loft conversion?   

The main advantage of a Mansard conversion is the ample extra space it delivers, effectively adding another storey to your home. The vast space can form an airy open-plan design or be divided into rooms, such as a master bedroom and bathroom, home office and bedroom, or large chill out pad/family room.

It is also likely to increase the value of your home substantially. According to a recent study, a loft conversion could push the value of a London home up by almost 25% – try our loft conversion ROI calculator.

A Mansard is also suited to a wide variety of London house styles, particularly classic Victorian and Edwardian terraced and semi-detached homes.   

The exterior can be finished in a range of materials, from slate or brick cladding to timber or render, perfectly complementing the existing aesthetic of your property.

Do I need planning permission for a Mansard loft conversion?

Due to altering the roof structure to a 72-degree angle it is usual to have to seek planning permission for a Mansard loft conversion. Depending on where you live in London there may also be criteria the conversion needs to meet to ensure it matches the character of neighbouring homes.

We can advise and support you in obtaining any planning permission your conversion might need. 

If you are adding a Mansard to a terraced or semi-detached home, it is also likely that work will be required to the party wall you share with your neighbours. Again, we can advise on steps to take to ensure neighbours are informed and agree with the work before your conversion starts leading to a smooth, stress-free build.      

How much does a Mansard loft conversion in London cost?

A Mansard is often the most expensive loft conversion due to its size and skilled construction work that goes into the build. Further factors that increase the cost are planning permission fees, plus additional work needed to the shared party wall. 

Once complete however, a Mansard creates considerable new space that you can enjoy, and if you come to sell, is likely to significantly increase the asking price of your home.

The average cost of a Mansard loft conversion in London is between £38,000 and £48,000.

What space can I create with a Mansard loft conversion?

A Mansard creates ample habitable space. We work with clients to realise an array of living spaces including:

Mansard loft bedroom en suite: If you’re outgrowing your home and craving extra room for yourself, children or guests, a Mansard loft conversion creates space for one or two bedrooms and en suite bathroom.

This generous L-shaped Mansard loft conversion completed in South West London features two bedrooms, en suite and French doors leading to a private rooftop terrace.       

Mansard loft Home office/Music room/Lounge/Chill out room:

A Mansard’s generous proportions can create a multi-functional space to suit your lifestyle. Popular options include a home study with additional bathroom, a teenage den for playing games and sleepovers, a spacious music room and additional living room.       

This Mansard loft conversion in South East London provides a music room and relaxing bathroom. French doors with exterior metal rail bathe the room in natural light.   

See these Mansard Loft Conversion Ideas for inspiration.

Why choose Absolute Lofts to design and install your London Mansard loft conversion?

  • Over three decades’ experience constructing bespoke Mansard conversions in London and South east
  • Full Project Management from support with planning permission through to quality construction and interior decoration
  • Absolute Value Promise fixed-price loft conversion and price match promise
  • Expert Design and Construction Team including RIBA architects and Federation of Master Builders (FMB) registered builders
  • Consumer Protection Insurance backed deposit and 10-year structural guarantee for complete peace of mind.

To arrange a free, no obligation estimate get in touch with us today.