Permitted developments

Many householder projects such as extensions, garage and loft conversions may not need planning permission.  It all depends on the size and scale of the work.

You can find out more about permitted development rules on the Planning Portal. Or read the guidance notes below:

Single storey rear extensions to dwellings - new "permitted development" provisions which involve a neighbour consultation process.

The size limits will double from 4 metres to 8 metres for detached houses and from 3 metres to 6 metres for all other houses. These new larger extensions (i.e. if they extend between 4 and 8 metres, or between 3 and 6 metres) must go through the following process:-

1. A homeowner wishing to build a larger single storey rear extension must notify the local planning authority (LPA) and provide:-

  • (a) a written description of the proposal which includes the length that the extension extends beyond the rear wall of the original house, the height at the eaves and the height at the highest point of the extension;
  • (b) a plan of the site, showing the proposed development;
  • (c) the addresses of any adjoining properties, including at the rear;
  • (d) a contact address for the developer and an email address if the developer is happy to receive correspondence by email.

A fee of £96.00 is required for the Larger Homes Extension application.

2. The LPA may ask for further information if it needs it to make a decision about the impact of the development on the amenity of adjoining properties.

3. The LPA will serve a notice on adjoining owners or occupiers, i.e. those who share a boundary, including to the rear. This will give the address of the proposed development and describe it, including the information in 1(a) above. It will also set out:-

  • (a) when the application was received and when the 42 day determination period ends;
  • (b) how long neighbours have to make objections (which must be a minimum of 21days) and the date by which these must be received.

A copy of this notice must also be sent to the developer.

4. If any adjoining neighbour raises an objection within the 21 day period, the LPA will take this into account and make a decision about whether the impact on the amenity of all adjoining properties is acceptable. No other issues will be considered.

5. The development can go ahead if the LPA notifies the developer in writing either:-

  • (a) that as no objections were received from adjoining neighbours it has not been necessary to consider the impact on amenity, or
  • (b) that following consideration, it has decided that the effect on the amenity of adjoining properties is acceptable.

6. If the LPA does not notify the developer of its decision within the 42 day determination period, the development may go ahead.

7. If approval is refused, the developer may appeal.

8. The extension must be built in accordance with the details approved by the LPA (or, if no objections were raised or the LPA has not notified the developer of its decision, the details submitted), unless the LPA agrees any changes in writing.

9. The development must accord with all other relevant limitations and conditions which currently apply to other rear extensions allowed under "Permitted Development" rules:-

No more than 50% of the curtilage of the property may be built on (the calculation excludes the area occupied by the original dwelling).

Maximum height must not exceed 4 metres.

Maximum height of eaves where development is within 2 metres of a boundary must not exceed 3 metres.

Materials used must be similar in appearance to the existing dwelling unless the extension is a conservatory.

10. To benefit from these permitted development rights, the extension must be completed on or before 30 May 2019.  The developer must notify the local authority in writing of the date of completion.

These rules do not apply within conservation areas, areas of outstanding natural beauty or sites of special scientific interest, where the existing restrictions on length of rear extensions of 3 and 4 metres continue to operate.

The requirements of the building regulations will continue to apply to extensions to dwellings.

Change of use to class C3 (dwellings) from class B1(a) (offices) provided that this takes place on or before 30 May 2016 subject to a "prior approval" process to deal with transport, contamination and flooding impacts described in more detail below.

Change of use to a state funded school from uses within classes B1 (business), C1 (hotels), C2 (residential institutions) and D2 (assembly and leisure) subject to the same "prior approval" process as above. Changing back to the previous lawful use is also permitted.

Change of use of a building and its curtilage from use as an agricultural building to a flexible use falling within either Class A1 (shops), A2 (financial and professional services), A3 (restaurants and cafés), B1 (business), B8 (storage and distribution), C1 (hotels) or D2 (assembly and leisure). The upper floorspace limit is 500 sq. m. and applies to buildings that have been solely in agricultural use since 3 July 2012 or for buildings brought into use after that date have been solely in agricultural use for 10 years. Flexibility means that the use can subsequently change from one to any other of the uses listed. Where the floorspace does not exceed 150 sq. m. the developer needs to inform the LPA of when the proposed use is to commence, which use it is to be and the building/curtilage to which it applies. For buildings which individually or cumulatively exceed 150 sq. m. but not 500 sq. m. there is a "prior approval" process, but with the addition of an assessment of noise impact.

An amendment to the current provisions for temporary uses permits the use of any building and land within its curtilage as a state funded school for a single academic year. This provision may only be used once and the site reverts to its previous lawful use at the end of the academic year.

Change of use to a flexible use within Classes A1, A2, A3 or B1 from a use within Classes A1, A2 A3, A4 (drinking establishments), A5 (hot food takeaways), B1, D1 (non-residential institutions) and D2 for a single continuous period of 2 years from the date the first flexible use commences. This applies to no more than 150 sq. m. of floorspace in a building. The developer must notify the LPA of the date the use will commence, which use it shall be and also notify of any further permitted change(s) proposed within the 2 year period. At the end of the period the site reverts to its previous lawful use.

The maximum size of buildings which are permitted to change from Class B1 or B2 to Class B8 or from B2 or B8 to B1 is increased from 235 sq. m. to 500 sq. m. There's no time limit on this provision.

The permitted sizes of new industrial and warehouse buildings and extensions to such buildings within the curtilage of existing premises are increased for a temporary period up to 30 May 2016 as follows:-

For new buildings the increase is from 100 to 200 sq. m.

For extensions the increase is from 25% to 50% subject to an upper limit of 1,000 sq. m.

These provisions don't apply in conservation areas or within the AONB.  The current limitations on height, proximity to boundaries and the requirement that there must be no reduction in parking or turning space remain in force. The developer must also notify the LPA in writing of the size of the development and when it was completed.

The permitted size for extensions to offices, shops, catering, financial or professional services premises is increased from 25% or 50 sq. m. to 50% or 100 sq. m., whichever is the lesser, for development completed on or before 30 May 2016. Height and proximity to boundary restrictions apply. The provisions don't apply in Conservation Areas or within the AONB. The developer is required to notify the LPA as above.

The current provision which requires developers to go through a "prior approval" process for the construction, installation or replacement of telegraph poles, cabinets or lines for fixed broadband services in Conservation Areas and the AONB is removed for such developments provided that they are completed before 30 May 2018.

The current "permitted development" limit on the height of walls, fences and gates which may be constructed adjacent to a highway of 1 metre is increased to 2 metres for schools only subject to the additional height not creating an obstruction to view likely to cause a danger.

In the circumstances described above, where in order to benefit from the new "permitted development" rights a "prior approval" process must be followed, this could result in permission being refused, which would then be subject to a right of appeal. The process involves:-

The developer providing the local planning authority (LPA) with a written description of the proposal together with a plan showing the site and the proposed development together with the appropriate fee.

The LPA determining whether the issues raised require consultation with the Highways Agency, Local Highway Authority or Environment Agency. If they do determine that consultation is required, the developer may need to provide additional information on transport and/or flooding impacts. Information on contamination risks and noise impact may also be required.

Publicity by site notice or neighbour notification is part of the process to be carried out by the LPA.

The LPA must make a decision to approve or refuse within 56 days. If it does not do so the development can go ahead anyway.

Need further help or information?

Contact the team directly on 01773 841571 or email