Planning Permission: Permitted Development

ABOVE: This impressive extension in West London did not, unfortunately for owner Anne Katrine Dolven, fall within PD rights. The reason — her early- Victorian terrace enjoys listed status, and the proposed extension was marginally visible from the road. (The use of different cladding to the original building, means such an extension would not fall under PD for any other home either.) The result — a threeyear planning battle with the LPA. “Everyone around here builds without permission,” says Anne. “We tried to do everything correctly and were punished.” Luckily for Anne, the intervention of Commission for Architecture and the Built Environment enabled permission to finally be granted. (Read more about this extension).

Do I need planning permission to extend my home?

Not necessarily, you may be able to carry out the work under Permitted Development (PD) rights. The concept of Permitted Development was introduced at the very beginning of our planning system – in the Town and Planning Act on 1st July 1948 – and allows for minor improvements, such as converting a loft or modest extensions to your home, to be undertaken without first applying for planning permission. Scotland, Wales and Northern Ireland each benefit from their own version of these rules.

The latest amendments to the PD rules were brought into force in October 2008 and are available in full on the Planning Portal website (planningportal.gov.uk).

Will my home benefit from PD rights?

Most likely yes, but there are a few things to bear in mind. Unfortunately, the slate is not wiped clean when you buy a home — any space added by past owners since 1948 counts towards your PD allocation. Alternatively, if you’re planning to self-build a replacement dwelling and your proposed new home is bigger than the existing house on site, then your PD rights are likely to be restricted or even removed on condition of granting planning permission.

Under the current PD rules, LPAs now have more power to apply what’s known as an ‘Article 4 Direction’ to remove the PD rights of historic homes or homes within protected areas. If your home stands in a Conservation Area or is listed, then you’re more than likely to need planning permission for minor work. So, before making any plans, talk to your LPA to find out your home’s status.

My home benefits from PD rights, how far can I extend?

Under the new rules, the ‘original’ (as it stood in or prior to 1948) rear wall of a detached home can be extended by up to 4m in depth with a single storey extension; this is reduced to 3m if you live in a semi or terrace. If your proposed new extension will be within 3m of a boundary, then the eaves height is limited to 2m under PD.

If you hope to build a two storey extension (no higher than the house), this can project up to 3m from the original rear wall, so long as it is at least 7m from the rear boundary. It’s also important to note that no extension can project beyond or be added to what is deemed to be the front of the house or an elevation which affronts the highway. And a side extension can not make up more than half your house’s width.

Furthermore, with the exception of conservatories, new extensions must be built of materials ‘similar in appearance’ and with the same roof pitch as the main house. So while PD rights are beneficial, there’s a lot to consider before starting work.

Is there anything else I can do under my PD rights?

Prior to the new legislation, volume limitations were applied to the entire house — so if you extended, you were unlikely to be able to convert your loft under PD rights as well. The good news is that the latter has now been separated out, allowing you to undertake both without one restricting the other. So, you can also convert your loft into a bedroom or extra living space by up to 50m³ in a detached house, or by 40m³ within any other home. Flush rooflights or those which do not project further than 150mm are permitted, but you will need permission to add a dormer window on any roof elevation which faces the highway.

You’ll also be able to add solar panels – subject to condition – but installing a wind turbine still needs planning permission. There’s also greater flexibility to add outbuildings — and more besides.

Further Advice on Planning

• Planning Permission: Making an Application
• Planning Permission: Obligations
• Planning Permission: The Party Wall Act

Further reading:

• A Guide to the New Permitted Development Rules
• Using Permitted Development Effectively
• Find out more about planning issues from our team of experts