Larger home extensions

It is possible to build some larger single-storey rear extensions under permitted development. The size limits are 8 metres for detached houses, and 6 metres for all other houses.  

You need to submit a householder application if your property is within a conservation area. 

You must not start development until you receive written notification from us stating that either: 

• prior approval is not required; 
• prior approval is required and given; 
• or the expiry of a period of not less than 42 days following the date on which the information was received by us and no written notification has been sent to the developer as to whether prior approval is given or refused.  

Before making an application: 

• read the guidance notes 

• check for any local planning constraints (restrictions) which may affect your plans 
• check if your scheme falls within the limitations of the larger home extension neighbour consultation scheme 

If you are still unsure then you can submit a Householder Development Enquiry to establish what permissions you may need. 

Applications 

You can submit your application by downloading and completing an application form and sending it to us.  

You can also download help text and guidance notes to help with completing the application form. 

Fees 

The fee for a notification of a proposed larger home extension is £96.  

Find more information on how to pay your fees or if an exemption applies. 

What happens next 

Processing the application 

We 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. It will include the information above. It will also set out: 

• when we received the application and when the 42-day determination period ends 

• how long neighbours have to make objections (which must be a minimum of 21 days), and the date by which we must receive these 

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

If any adjoining neighbour raises an objection within the 21-day period we will take this into account. We make a decision about whether the impact on the amenity of all adjoining properties is acceptable. 

We do not consider any other issues.  

Starting the development 

The development can go ahead if the local authority notifies the developer in writing either: 

1. That as no objections were received from adjoining neighbours it has not been necessary to consider the impact on amenity, or 

1. That following consideration, it has decided that the effect on the amenity of adjoining properties is acceptable. 

• If we do not notify the developer of our decision within the 42-day determination period, the development may go ahead. 
• If approval is refused, the developer may appeal. 

• The extension must be built in accordance with the details approved by us (or, if no objections were raised or we have not notified the developer of its decision, the details submitted), unless we agree any changes in writing. 
• The development must accord with all other relevant limitations and conditions which apply to other rear extensions allowed under permitted development. These are set out in Class A, and include for example, the requirement that the extension (apart from a conservatory) must be constructed using materials of a similar appearance to those used in the construction of the rest of the house.