Our Permitted Development Guide

Find out what you can do to your home without the need to apply for planning permission

Whether you’re simply looking to improve your existing house or carry out major works to one you’re intending to buy, it pays to understand the scope of the available Permitted Development rights.

They are granted in the form of General Development Planning Orders (GDPOs) which apply separately to England, WalesScotland and Northern Ireland, and, in effect, they give implied planning consent to carry out certain classes of development.

In order to carry out work under Permitted Development the work must strictly conform to the current criteria, so it does make sense to either check with your local authority before carrying out the works or have a qualified surveyor confirm that they are in order.

An increasing number of local authorities offer a consultancy service for a small fee, and will confirm in writing whether or not a planning application is required. This can be very useful when it comes to reselling the property within the first four years of completion.

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Will my home benefit from Permitted Development 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 Permitted Development 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 Permitted Development rights are likely to be restricted or even removed on condition of granting planning permission.

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

Under the rules, the ‘original’ (as it stood in or prior to 1948) rear wall of a detached home can be extended (subject to the neighbour consultation scheme) by up to 8m in depth with a single storey extension; this is reduced to 6m if you live in a semi or terrace. If your proposed new extension will be within 2m of a boundary, then the eaves height is limited to 3m under Permitted Development. Otherwise, a single storey rear extensions must be no higher than 4m.

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 Permitted Development rights are beneficial, there’s a lot to consider before starting work.

Is there anything else I can do under my Permitted Development rights?

In the past volume limitations were applied to the entire house — so if you extended, you were unlikely to be able to convert your loft under Permitted Development 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.

However, you cannot cover more than 50% of the land around your house with extensions (including extensions by previous owners), and you have to include any outbuildings when calculating this coverage. Sheds and other outbuildings count in this calculation.

Improvements: What you can do

  • Build a porch.

  • Carry out internal alterations.

  • Convert and occupy the loft space.

  • Install microgeneration equipment such as solar panels (apart from wind turbines).

  • Install satellite dishes.

  • Erect antenna.

  • Put in rooflights or dormer windows.

  • Put in new doors or windows.

  • Extend the back of your home.

  • All subject to design constraints; e.g. porch has to be less than 3m³, rooflights and dormers must not face the highway, etc.

Extensions: What You Can Do

  • You can extend a detached dwelling by 8m to the rear if it’s single storey or 3m if it’s double.

  • Semi-detached and terraced homes can be extended up to 6m to the rear of the property if single storey.

  • There are height restrictions but they boil down to a single storey extension not being higher than 4m in height to the ridge and the eaves, and ridge heights of any extension not being higher than the existing property.

  • Two storey extensions must not be closer than 7m to the rear boundary.

  • It must be built in the same or similar material to the existing dwelling.

  • Extensions must not go forward of the building line of the original dwelling.

  • Side extensions must be single storey, maximum height of 4m and a width no more than half of the original building.

  • In Designated Areas side extensions require planning permission and all rear extensions must be single storey.

  • An extension must not result in more than half the garden being covered.

  • You can only do it once and the original building is either as it was on 1st July 1948 or when it was built. In Northern Ireland it is as it was built or as it was on 1st October 1973.

Outbuildings: What you can do

  • You can construct all sorts of outbuildings for the use and enjoyment of the home so long as they do not cover more than 50% of the garden space. In Scotland this is reduced to 30%.

  • In Wales and Northern Ireland any outbuildings closer to the house than 5m count as extensions. In Scotland any outbuildings larger than 4m² and closer to the dwelling than 5m count as extensions.

  • Outbuildings must be single storey with a maximum ridge height of 4m for a pitched roof or 3m for any other kind of roof. The eaves height must be no more than 2.5 metres.

  • If the outbuilding is closer to the boundary than 2m it shall be no higher than 2.5m.

  • No outbuilding can be forward of the original dwelling. In Wales and Northern Ireland the same applies unless the resulting building would be more than 20m from the road.

Conversion of Non-Domestic Buildings into Homes

Under Permitted Development, existing buildings – such as offices, barns and other agricultural buildings – can be converted into homes.

Agricultural Buildings and Barn Conversions

In March 2013 a new system was introduced to allow the conversion of barns into dwellings. Permission would still be required via the prior approvals process, but it created potential for more conversion opportunities than before. Read more here.

Former Office Buildings

In an attempt to release inner-city land for housing, the next change in Permitted Development was an announcement in May 2013 to allow offices to be converted to residential. This was set to expire in 2016, but in October 2015 it was declared that these rights would be made permanent.

Did you know…?

Balconies, verandas and raised platforms (above 300mm) do not fall under Permitted Development rights. You will also now need planning permission to construct a drive from non-porous materials such as tarmac. But you can construct a new drive of porous materials, or non-porous if provision for drainage is provided on the property, under Permitted Development.

For more details on the rules see the Planning Portal announcement.