Transform your home with a Mansard Loft Conversion.


Thinking about expanding your property’s living space? If so, you might indeed want to consider Mansard’s loft conversion.

Mansard loft conversions offer an inventive design transformation to a home, allowing for the addition of dormer windows in a newly constructed roof between 72 and 90 degrees. This loft design will enable homeowners to use previously unusable space with custom-made dormers maximising natural lighting.

Since the 16th century, Mansard roofs have graced many of Paris’s grandest structures – including part of the iconic Louvre museum. With this type of loft conversion, that same classic look can now be achieved in any property type. Although it tends to be more costly than a conventional loft conversion, it can transform a property into something quite special.

Mansard Loft Conversion Benefits

  • This Is the best way to maximise the space available.
  • Dormer windows are used in Mansard loft conversions, providing abundant light.
  • These adaptations only require a few structural reinforcements.
  • Since the interior of these loft conversions consists mainly of vertical walls, furnishing and decorating are straightforward.
  • The loft area is a different storey rather than a modified loft.

Mansard Loft Conversion Possible Downsides

Because all the changes made to the roof structure may be costly, more so than a dormer or hip-to-gable conversions.

Planning approval will be required, but the finished article will be well worth all the red tape and hassle. A Mansard loft conversion can add an updated modern feel to your property. Just be aware that this type of roof extension is considered substantial as it changes the character and appearance of the roofline and exterior, which means planning permission from your local authority before proceeding is necessary.

In order to provide a significant amount of extra space and maximise head height, this sort of conversion is erected along the full roof plane of a house. Mansard conversions often sit in the back of a home, although they can occasionally sit at the front. The wall of the expansion slopes backwards at a 72-degree angle, and a Mansard roof is level with a slight fall to accommodate water drainage.

These expansive, fashionable loft conversions are common in the suburbs, even in London, where homeowners frequently look for new methods to add additional living accommodation to their properties. Often Mansards are large enough to accommodate numerous room arrangements, including a bedroom and bathroom, a study, a games room etc. the limits are endless and only limited to one’s imagination. Some even have balconies!

Many people appreciate how Mansards provide the impression of an additional floor rather than a more aesthetically appealing modified loft. The outside finish of the building should be matched to the existing brickwork, fascias, soffits, gutters, and new windows to integrate with the original building, all guaranteed by a specialised contractor. Vertical Mansard walls offer lots of room for furnishing and décor.

Mansard loft conversions are a great way to boost the value of your home while providing more room for entertaining, working or relaxation.  

With the help of professionals, this extension can be completed quickly despite its complex structure and extra cost. Remember that you will need planning permission and approval before the project commences.

Things to consider for your Mansard projects.

A Mansard roof conversion is the best option if your conversions objective is to maximise the amount of usable space in the loft area. They may add much-needed extra square footage to your home while significantly increasing its value.

Mansard roofs are appropriate for most house styles, including terraced, semi-detached, and detached homes, and are particularly well-liked for historical buildings. But, before beginning work on the conversion, like with any house improvement, you must consult with your local planning authority, informing them of your intentions.

Mansard home extensions have been a hot topic for debate among planning officers, committees and even the courts over whether they should be allowed in conservation areas. Despite much deliberation, getting approval for adding such an extension can still

be challenging if you live in a terraced house with entire rows of houses with traditional roofs. The suitability of your house would need to be assessed for a Mansard conversion by a professional loft surveyor, who will outline the pros and cons. 

Most important, according to the Party Wall Agreement Act of 1996, if you own a terraced or semi-detached property, you must notify your neighbours and obtain their formal agreement before beginning any construction.

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One of the crucial parts when deciding on a loft conversion is largely determined by size, location, design complexity and internal fittings. 

The price of a mansard loft conversion might vary depending on a number of factors. The following are important considerations:

  • Cost/budget
  • Purpose of converting the loft 
  • Conversion planning
  • Existing roof structure 
  • Planning permission
  • Plumbing/electrics
  • Any hazardous materials

For instance, Mansard conversion prices start at roughly £40,000 and take around eight weeks to complete, depending on where your location and your project specifications. A double bedroom loft with a simple roof light could cost as little as £18k, but including an en suite and dormer window can quickly take prices up to around £40k or beyond. At the high end, you may be looking at budget costs of over £65K.

The last thing you need is to overlook a cost that has appeared on the final invoice/payment that wasn’t agreed to.

Once you have your quotation from the contractor, check if all has been accounted for (materials/time/clearing site/waste disposal etc.) so there won’t be any unaccounted additional fees! Check your specification. Has everything been factored in? And don’t expect the contractor to do something for free if it wasn’t included in the quotation that both parties should have agreed to and signed. 

When budgeting, remember the VAT factor; yes, we all have to pay it. Before hiring contractors for your loft job, ensure you know the local authority regulations. Plus, their fees that can impact your budget, i.e., loft planning permission, development certificates, structural engineers and a party wall, all come at a cost, whether in time or money, and all need to be factored in. 

Given the comprehensive nature of Mansard construction, we advise hiring a professional consultant to assist you throughout the whole process to ensure each stage of the project goes according to plan. 

It also pays to enlist the services of a professional architect as they will act as valuable partners – balancing quality with the price so that when all’s said and done, you have something that meets your expectations. Working alongside an architect allows for individualised solutions and possibly some budget savings.


The evolution of CAD (Computer Aided Design) technology enables a closer design relationship between clients and architects, allowing for greater personalisation to meet your exact needs. It allows both parties to explore their design from all new angles and be able to visualise the finished article. It’s a great way to reach an agreement on specific design features.

Professional architects can provide impartial information to ensure your completed project meets your approval.

Then let the Loftteam help you to realise your London property’s potential with a Mansard loft conversion.

For a more comprehensive look into our services, be sure to check out the home extension page on our website!

Our specialist team in London is here to provide expert advice on which style would be best for your property – get in touch today!

When your loft project is complete, you will have a stunning new space that compliments your property!


Loft Conversion

Home Extension 


Interior Design 

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