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Mansard Loft Conversions – All you need to know

Mansard loft conversions often require more construction work than other types of loft conversions, but can result in creating a great deal of extra living space in your home, whatever type of property you own.

What is a Mansard Loft Conversion?

Named after the 17th Century French architect, Francois Mansart, mansard loft conversions can be thought of as an extension across the entire plane of your property’s roof. Often found at the rear of properties, this type of conversion changes the sloping side of your roof to an almost vertical side – one of at least 72 degrees. The roof is flat and windows are typically housed within small dormers. Why not try our loft conversion calculator to get a rough estimate on price.

Mansard Loft Conversion

Do you need planning permission for a Mansard Loft Conversion?

Planning permission is almost always required for this type of extension. These conversions create maximum living space within your roof by effectively creating another storey to your property. As this results in changes to the roof shape and structure, it is highly likely that planning permission will be required from your local authority.

How much do Mansard Loft Conversions cost?

This type of loft extension is often more expensive than other types, such as a dormer or hip-to-gable conversion.

Mansard loft conversions create a great deal of space, ultimately through changing the structure of a roof significantly, and therefore often require more work than other types of conversion. This therefore typically makes mansard conversion prices fall at the more expensive end of the scale. Ultimately you get what you pay for, but if you would like more specific price estimations please get in touch with us for a free quote.


mansard loft conversion london

Is your property suited to a Mansard Loft Conversion?

Mansard roofs are particularly common in London and other urban areas and can often be seen across whole rows of older terraced properties. Although not regularly seen in suburban areas – flat roof dormers are typically cheaper and simpler to construct – mansard roofs are actually suitable for almost all types of properties. Detached, semi-detached and terraced houses, as well as chalets and bungalows, can all typically house mansard loft conversions.

In terms of aesthetics, the external walls of a mansard extension can be exposed brickwork, rendered or clad with slate or tile – whichever best fits with your property!

Pros and cons of Mansard Loft Conversions

Pros include:

  • Creates maximum space in the roof of your existing property.
  • Suitable for many different types of property.
  • Can be finished in a number of ways to match the existing building style.

Cons include:

  • Planning permission is almost always required.
  • Often more expensive when compared to other types of conversion.
  • Require considerable amount of construction work.


mansard loft conversion london

Mansard Loft Conversion Ideas

As we’ve discussed, mansard loft extensions involve adding a great deal of space to a property, and so are often thought of as more like extensions than just a conversion.

This extra space, often amounting to an extra storey, can be used for a whole host of purposes. Most simply, a mansard loft conversion can be used to provide extra living space, in the form of a study, office, lounge, playroom, a gym or even for extra bedrooms.

Alternatively, the conversion can house extra bathrooms if the required plumbing work is carried out – the possibilities are endless.

To discuss your mansard loft conversion ideas and plans, contact us today or request a free, no-obligation quote online.