Self build exemption - residential extension

There are three types of self build exemption:

  • self build exemption - for a whole house
  • self build exemption - for a residential annexe
  • self build exemption - for a residential extension

The exemptions apply to anybody who is building, or commissioning, their own home, residential extension or residential annex. Individuals claiming the exemption must own the property and intend to live in it as owner-occupier for a minimum of 3 years following completion.  

Residential extension

If the new build floorspace of your residential extension is 100sqm or more, then you will be liable for CIL. Residential extensions below 100sqm are already exempt from the levy under the minor development exemption.

You can apply for exemption from CIL if you are building a residential extension. You must have a material interest in the main dwelling (own or have a leasehold of seven or more years). Any extensions must be an enlargement to the main dwelling.

Claims for a self-build exemption for a residential extension should be submitted using the relevant CIL form. This form is available using the link below.

The claim must be accompanied by an assumption of liability notice before starting any work.

Important note

It is important that you don't begin work until you submit your application for exemption and you receive notice from us with a decision. If you start any work, including digging foundations, your application for exemption will be refused and payment of CIL will be due.

 

State aid

Self build exemptions cannot be granted if they would constitute a notifiable state aid.