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Lofts and loft bathrooms


Lofts and loft bathrooms

With many of us having decent sized lofts in our homes, converting them is one of the most popular home improvement projects we oversee.  Often the loft will be turned into extra bedroom space, incorporating a bathroom or ensuite.

Loft size

The simplest type of loft conversion, if headroom allows, is to leave the existing roof intact and add rooflights. Many properties built before 1960 have steep pitched roofs which allow for this simpler type of conversion.  However, if you don’t have this type of roof, an architect/agent can help you decide on a design which can incorporate adaptions to the roof such as dormers or a mansard window to provide more floor space and open up views. 

Planning permission

Usually loft conversions don’t require planning permission unless you are in a conservation area, own a listed building or are altering the roof line but you should always check with your local planning department and you can visit the Planning Portal interactive house here for more information. 

If you live in a property adjoining another, don’t forget you must tell your neighbour if you want to carry out building work near or on your shared property boundary or ‘party wall’ if you live in England or Wales. Read more on Party Wall Agreements here.

Access and structure

To be classed as a ‘habitable space’ a loft must lead from a permanent staircase with a head height of 2m.  There are strict regulations regarding fire and escape routes too, which mean you will need to ensure you install specific types of windows and doors as well as adhere to other Part B building regulations.

The structural integrity of your loft conversion is fundamental and a structural engineer will be able to work out calculations for you regarding load (weight) and any additional support needed for the new living space. For example, ceiling joists will usually need strengthening and if you have a trussed roof it is likely to need extra support.  Bear in mind your new floor may need to be extra sturdy if you are installing a bath as these can be especially heavy when filled with water.

Drainage to your bathroom

As the loft is the highest point of your house there can be issues surrounding the required drop and angle of pipework to ensure good drainage and getting water to the bathroom. A good plumber will look at your boiler capacity and water pressure and a pump system can be a good option, whilst an electric shower can help ease household demand.

Ventilating your loft bathroom

To avoid condensation and potential mould issues you will need an extractor fan and/or a good-sized window.  In your loft this is even more important as heat rises and building control will need to check that your ventilation mechanism meets the building regulations.


As our previous blog on Bathrooms and Part P electrical work explained, bathrooms need careful planning for many reasons and this is especially true in the loft area to ensure compliance with building regulations.

Applying for building regulations

We would always suggest you ask friends or neighbours for recommendations of good builders they have used. Make sure you obtain written quotes so that you can compare them like for like, ask to see the standard of their work and check they are familiar with your type of project before deciding who to employ.

As a loft conversion is a ‘material change of use’ you will need to make an application to building control before you start work. For more information see the LABC website information here or read the section on loft conversions in our Guide to Extending your Home here.

If you would like to talk to us about your project, please get in contact on 0330 0249355 or email us at



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