1/2
 

REAR MANSARD LOFT CONVERSIONS

Example planning drawings, questions and answers and more...

One of the more specialised  types of Loft Conversion we design are what is known as "Mansard Loft Conversions". For owners of terraced or end of terrace houses this type of Loft Conversion often represents an interesting alternative to a more straightforward Flat Roof Dormer.

On this page we have the answers to a few of the most common questions we are asked about Mansard Loft Conversions and a few sample Planning Drawings for you to look at. If you are interested in having us draw up some Loft Plans for your Mansard Loft Conversion please get in touch!

 

Q1. What is a Rear Mansard Loft Conversion?

A Hip to Gable Loft Conversion is a type of loft conversion where a "Hipped End" of an existing roof is changed to form a "Gable End", in order to provide more space internally. As the graphics below illustrate the term "Hip to Gable" may only be a partial description of the work. In most cases a loft conversion which incorporates a "Hip to Gable" will also include the addition of a rear dormer as well. For example the project illustrated below would be more accurately described as a "Hip to Gable Loft Conversion with a Flat Roof Dormer". Think of it like this:

 

ADDING A FLAT ROOF DORMER

Adding a flat roof dormer to the existing roof creates a much bigger internal space to work with. Standing space is usually more than doubled and this is often crucial enabling the creation of a space big enough to accommodate a bed, wardrobes, the new stairs, a en-suite with a shower etc.

Hip to gable loft conversion.jpg

EXISTING GABLED ROOF

This is an example of a typical gabled roof. The roof consists of two pitched roofs which form a triangle over an end wall. It is this triangular end wall which is known as a "gable". Although there is often a reasonable amount of space within a gabled roof/ loft that space is of limited use when it comes to creating loft rooms. Headroom for standing is usually restricted to the highest part of the roof space only and it can be very difficult to design a new staircase to work harmoniously with the existing roof.

Hipped roof.jpg

ADDING A FLAT ROOF DORMER

Adding A Mansard Loft Conversion is a Loft Conversion where an existing Gabled Roof is extended out to create more space by building a special type of Dormer. As the graphics below show a Mansard Loft Conversion usually involves building up the flanking walls at either side of the property and constructing a very steep pitched roof between them to act as the rear Dormer wall. Small "Pocket Dormers" can be built into this new roof to accommodate vertical windows and doors. It works like this: 

Gable end loft conversion.jpg

Q2. Does a Rear Mansard Loft Conversion require planning permission?

Whether or not you need to apply for planning permission in order to carry out a Rear Mansard Loft Conversion on your house depends on a few factors. For most houses the answer is a simple no - you do not need to apply for planning permission because the work can be carried out as permitted development (read more about those here. However, not every house has Permitted Development Rights and sometimes those rights are not sufficient for the project so there are plenty of instances where Planning Permission does need to be sought. This is especially true for houses which are located in conservation areas, or have been extended previously and have therefore used up some of the "cubic volume" allowance provided by Permitted Development Rights.

 

Q3. Is my house suitable for a Rear Mansard Loft Conversion?

This is a really difficult question to give a straight answer to because each situation really ought to be individually assessed. There are lots of variables to consider and even in very difficult situations a solution can often be found if the client is determined enough and willing to consider solutions which are more disruptive and expensive than usual. However, if you want a few simple points to begin with you can start with these:

1. Is the existing loft space high enough?

A new floor will be installed as part of the loft conversion which will, if installed above the existing first floor ceiling, reduce head height in the loft. Roughly speaking if you can measure a clear 2.3 metres vertically between the top of the existing first floor ceiling joists and the underside of the existing timber ridge board (the board right at the highest point of the roof) then you should have enough height to form a room without having to lower the ceilings on the first floor.

2. Is there enough space to fit a new loft staircase over the existing staircase without having to move any walls?

Again this an area which really requires professional guidance (which we can provide). However, in some instances even a lay-person can see that a space looks too small to accommodate a staircase. If you think that might be the case in your situation, and you are particularly concerned about the potential loss then we strongly suggest you book a free consultation meeting to look at the issue. Alternatively an experienced builder or joiner may be able to offer you some guidance depending on their level of experience. Try to avoid the many online staircase design tools/ configuration software as they tend to be overly simplistic and lack functionality which is vital to designing loft stairs.

Q4. How do I prepare my Rear Mansard Loft Conversion project?

There is no one plan that will work in every instance but most loft conversion projects proceed more or less according to this road map:

Step 1 - Initial Design
Have the house surveyed and work through a design to formalise a set of Loft Conversion Plans which you would like to build.

Step 2 - Apply for a Lawful Development Certificate or Planning Permission
There is a much longer explanation available for you to read here but essentially planning consent needs to be obtained or confirmed.

Step 3 - Secure any other consents you may need
There are various other types of consent you may need to secure or conditions you might need to meet before you can start work on your loft conversion. For example, if you share a freehold you may need the other owners to consent to your converting the loft, if you bought a "new build" house then the original developer may have placed a restrictive covenant in your deeds saying some specific amount of time must pass before you can undertake any building works, or perhaps the planning authority applied a condition to the planning permission they granted which needs to be met ahead of the works beginning on site. There are too many possibilities to list here so you must satisfy yourselves that all of the requirements are met.

Step 4 - Serve Party Wall Notices
Again there is a much longer explanation you can read here but essentially if you share a wall(s) with your neighbour and the proposed works affect it then you will have to notify the affected neighbour(s).

Step 5 - Prepare Building Control Drawings and Structural Calculations
Before work can start on site an upgraded set of drawings will need to be produced along with a set of structural calculations. These are the main documents which will be used by Building Control to asses whether or not the proposed works comply with the Building Regulations and also by the builders working on site.

Step 6 - Appoint a Party Wall Surveyor (s) if needed*
If any affected neighbours do not consent to the proposed works, or if you or they would like to appoint a Party Wall Surveyor(s), then you will have to make the relevant appointments to draw up a document called a "Party Wall Award" ahead of the building works starting.

Step 7 - Submit paperwork to Building Control
Building Control need to be notified that the proposed works are going to take place and they will need plans and structural calculations to assess the proposals.

Step 8 - Appoint a builder and start work on site!

Q5. Which is the best approach for undertaking a loft conversion - Design and Build with a Loft Conversion Company or employ my own designers direct?

There are advantages and dis-advantages to both of these approaches and so neither ought to be described as "best" without understanding the context. We work both ways, sub-contracting our services to loft conversion companies and builders and also working directly for homeowners as well.

Homeowners who employ us direct do so for various reasons. Typically they either want to develop the design of their loft conversion without the commitment of having to proceed with building works after the design stage is complete, or they need to apply for planning permission for the project and want to be free to develop it without having to consult or re-negotiate with the contractor, or maybe they have a contractor in mind who they want to work with who does not offer a design and build service.

When we work with homeowners via a builder or loft conversion company to whom we are sub-contracted the scope of the project, its specification, its price etc are all generally agreed between those two parties independently of us. This gives the homeowner the comfort and confidence of knowing their total costs from the outset and also gives them a single point of contact to see them through the entire process. It's an approach which works very well on projects which are easy to quantify but is less advantageous on more complex projects.

SAMPLE LOFT CONVERSION PLANS

Example "planning issue" plans for Rear Mansard Loft Conversions

We have designed many rear mansard loft conversions down the years. Here are a few recent examples:

 
Want to know what we can we do for you, or how much we charge?

If you have a project in mind we'd love to hear from you so please get in touch.  We offer a comprehensive service which we think represents the best value for money available. You can read all about it here:

READY TO GET STARTED?

If you've already looked at our prices and want to get started the first step is to book a visit from one of our experienced design consultants. The consultant will take a look at the property and discuss the potential loft conversion with you. If the project is feasible and you are happy with what is suggested then our consultant will take a full site survey then and there so that we can move forward to getting some plans drawn up for you. If the project is not possible, or at least if it is not what you were hoping for then there is no further commitment. The survey isn't performed and we part company. There is no charge in that situation. We find this approach suits both parties as it avoids the need for return visits. 

To make an appointment you can either call the office on 020 3031 6628 or book online. It's easy.

 

Address

26 Kings Hill Avenue
Kings Hill
ME19 4AE

Contact

Follow

02030316628

©2020  All About Lofts Ltd