Know the rules before planning your extension

Big home improvements like loft conversions and extensions can often be done under your home’s permitted development (PD) rights.

It means you don’t need planning permission, as long as you stick to the rules governing width, height, materials.

You can apply to your local council for a lawful development certificate for building work that doesn’t require planning permission.

When you come to sell your home, this certificate can be really useful because it proves to the buyer and their solicitor that the work is lawful.

The PD rules can be different for different types of house – with loft conversions, the permitted size is 40 cubic metres in terraced houses, and 50 cubic metres in detached and semi-detached houses.

The PD rules can also be different on “designated land”, which includes conservation areas and Areas of Outstanding Natural Beauty. For example, loft conversions are not permitted development on designated land. If your home is listed, the rules are much stricter and even minor alterations can require listed building consent from your local council.

Flats and maisonettes don’t have PD rights and some houses have had theirs removed – this is sometimes the case on designated land. Permitted development isn’t just about major building work; if your home doesn’t have PD rights, you may need planning permission for things as simple as erecting a garden shed, decking your garden and painting the building’s exterior.

Until May 30, 2016, most houses (exceptions apply) can build a longer rear extension without planning permission than would normally be allowed under permitted development.

For detached houses, rear extensions can be 8 metres instead of 4 metres long, and for attached houses, 6 metres instead of 3 metres.

However, the council will consult your immediate neighbours about your planned extension and if any object, it can uphold their objection and refuse permission for the extension.

To find out about planning rules, go to www.planningportal.gov.uk, where the information includes guides to building projects and an interactive house and terrace.

However, the most accurate way to find out which rules and regulations apply to your home and proposed building project is to speak to your local council.

You may not realise, for example, that you live on designated land or in a house that has had its PD rights removed so it’s best to check it out.