Planning: Permitted Development Rights

What you're allowed to build without making a planning application

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Permitted Development Rights (‘PDRs’)

PDRs are a ‘free allowance’ that allow you to build extensions or conservatories etc without the need for a planning application. These are the basic rules:-


No extension allowed in front of your ‘principal elevation’ – normally the front main wall.

However small porches are permitted if :-

  • Under 3 sq metres floor area
  • Maximum 3 metres high
  • Set back at least 2 metres from roads or footpaths


Extensions are permitted to the side as long as they are single storey, subject to :-

  • Maximum height : 4 metres
  • Maximum width: up to half width of original house

N.B. if the side of your house counts as the ‘principle elevation’, e.g. where your side wall faces a highway – then no extension is allowed


Quite large extensions are permitted to the rear, both single and multiple storey. The size rules were increased temporarily from 2013 doubling the previous limits. So you can now build up to 8 metres deep for single storey rear extensions to detached houses, and up to 6 metres deep for terraced and semi-detached houses, or for extensions of more than a single storey to detached houses. Previously the limit was 4m and 3m respectively. The maximum height for single storey extensions remains at 4 metres.

However, a homeowner wishing to build an extension or conservatory greater than the previous Permitted Development limits will first need to write to the local planning authority providing plans and a description of the proposal. The local authority will then notify adjoining neighbours who will have 21 days to make an objection. If no objection is received the homeowner will be able to proceed.

If any neighbour raises an objection, the local authority will then consider whether the impact of the proposed extension on the amenity of the neighbours is acceptable. No fee should be charged for this.

Subject to…

If the above allowances sound too good to be true, bear in mind that some additional rules apply that may restrict what you can build:-


Extensions must be no higher than the highest part of the main roof

The eaves and ridge height must also be no higher than those of existing house

For extensions within 2 metres of a boundary, the maximum eaves height is limited to 3 metres.

And higher extensions of 2 storeys or more must be no closer than 7 metres to your rear garden boundary

Garden plot

You’re allowed to cover up to half the land around the ‘original house’ with buildings. This includes any previous extensions which must be taken into account (unless you demolish them). Once this limit has been used up you need planning permission.

Conservation Areas & Listed buildings

The rules are less generous for properties located in Conservation Areas. Here, no extensions are permitted to the front or side of the building, and to the rear they must only be single storey. But it could be worse – for Listed buildings nothing is permitted!

Planning conditions

When planning consent is granted for the development of new homes, it’s not unusual for a condition to be included that removes Permitted Development Rights. So if your property was built fairly recently, this should be checked. In fact it’s worth checking with the Planners anyway because PDRs are occasionally removed for other reasons, (e.g.‘article 4 directions’).


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