Guidance on Permitted Development Rights

What are permitted development rights?

Permitted development rights are rights to make certain changes to a building without the need to apply for planning permission.
They result from a general planning permission granted by Parliament, rather than from planning permission granted by the local planning authority.
Before some Permitted development rights can be used, the house/property owner might need to first obtain prior approval in relation to certain aspects of the development from their Local Planning Authority (See section on – Larger Homes Extension – Prior Approval) .

Permitted Development Rights for Extensions.

  • Single-storey rear extensions must not extend beyond the rear wall of the original house by more than 3m, if an attached house (semi detached/town house/ terraced) or by 4m if a detached house.
  • However, if you go down the Prior Approval Larger Home Extension route, then you can extend a detached dwelling by 8m to the rear, if it’s single storey or 3m if it’s double storey. Semi-detached and terraced homes can also be extended up to 6m to the rear of the property if single storey.
  • If the extension is within 2m of a boundary, maximum eaves height should be no higher than 3m to be a Permitted Development. Single storey extension cannot be higher than 4m in height to the ridge, and ridge heights of any extension must not be higher than the existing property.
  • Side extensions must be single storey, a maximum height of 4m and a width no more than half of the original building.
  • Two storey extensions can be 3m from the rear wall and must not be closer than 7m to the rear boundary.
  • Materials used in exterior work are to be similar in appearance to those of the exterior of the existing house. This condition does not apply when the extension is a conservatory.
  • Extensions must not go forward of the building line of the original dwelling. This building line is usually seen as the roadside elevation of the house; so no extensions at the front of the house.
  • Planning permission will be required for side extensions in in designated areas e.g. conservation areas, and rear extensions must be single storey.
  • 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.
  • Extensions (including previous extensions) and other buildings must not exceed 50% of the total area of land around the original house. Sheds and other outbuildings must be included when calculating the 50% limit.

Does every property have permitted development rights?

Many properties will be able to use a permitted development right to extend or alter their property. However, these rights will refer to the existing dwelling as first built; or as it stood on 1st July 1948, and so you cannot use these rights to put an extension on an existing extension. See notes earlier for details on what you can and can’t do.

In some circumstances Local Planning Authorites can suspend permitted development right in their area, under Article 4 of the Town and Country Planning (General Permitted Development) (England) Order 2015. So it is worth checking that permitted development rights apply to your project before you start work. Advice can be obtained from your local planning authority or Morton Architectural Design can also give you guidance.

Another consideration is if you are on a new build development the house builder may have put a covenant on your property with regard to extensions. This could mean you need to get their permission/approval before extending your new build home; and sometimes this can also incur a charge.

In some areas of the country, known generally as ‘designated areas’, permitted development rights are more restricted or do not exist, these include :

  • a Conservation Area
  • a National Park
  • an Area of Outstanding Natural Beauty
  • a World Heritage Site or
  • the Norfolk or Suffolk Broads.

In addition, if your house/building is listed then you will have to apply for planning permission as listed buildings do not have permitted development rights.

Larger Homes Extension – Prior Approval

In May 2013 changes came into force to allow permitted development for home extensions; to increase the size limits for the depth of single-storey domestic extensions from 4m to 8m (for detached houses) and from 3m to 6m (for all other houses), in non-protected areas, for a period of three years.

In order to confirm if you can achieve these extra length extensions you will need to apply to your Local planning authority via a Prior Approval Larger home Extension. This will involve a fee and consultation with neighbouring properties . This temporary permitted development was extended until May 2019 and the Government has announced that it will be made permanent.

Lawful development Certificate

If you want peace of mind that the extension you are planning to add to your home is allowed (under permitted development); then the best way is to submit an application for a lawful development certificate to your local council. You will have to submit sufficient information/scale site drawings for them to be able to make a decision; and if it is lawful, you will receive written confirmation from them. Fee’s will normally be incurred for both the application and the drawing up of the proposed plans.

New laws to extend homes upwards

As of September 2020, homeowners will now be able to add 1-2 storeys to their house under permitted development. As with all permitted development there are limitations, but if these are all met then planning permission will not be required.

You will still need to have some detailed plans and a Building regulations application completed, by someone like Morton Architectural Design, but without the time lag often associated with the planning process.

More information can be found on the Planning Portal :

With this being a new form of permitted development, we would recommend a Lawful development certificate application be made prior to starting any work on site

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