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Which Developments are CIL liable?

​CIL is charged on most new developments (new buildings or extensions) that involve the creation of one or more new dwellings, or 100 square metres or more of new gross internal floorspace. Developments involving the creation of new dwellings will be CIL chargeable even where the additional floorspace is below 100 square metres. 

CIL is not charged on the following types of development:

  • Development where the gross internal area of the new build floorspace is less than 100 square metres, and the development does not comprise of one or more dwellings (This is the ‘Exemption for minor development’ set out below).

  • The creation of, or works to, buildings into which people do not normally go, and buildings into which people go only intermittently for the purpose of inspecting or maintaining fixed plant or machinery.

  • Structures that are not defined as buildings, such as pylons and wind turbines.

  • Conversion of a single dwelling into two or more residential units, where no new floorspace is created. Extensions proposed as part of such a conversion will however be chargeable. 

What types of planning permission does CIL apply to?

CIL applies to the following types of planning applications:

  • Full planning permission.

  • Approval of reserved matters following an outline approval.

  • Removal or variation of a condition of permission (Section 73 applications).

  • Householder applications which involve an extension of 100 sq m or more.

  • Retrospective applications.

  • Applications granted after appeal, even where the application was appealed prior to the adoption of a CIL.

CIL also applies to:

  • Phased developments - each phase is treated as a separate development for the purposes of CIL.

  • New build floorspace of over 100 sqm that relies on ‘General Consent’ (permitted development).

CIL does not apply to permission granted for a limited period or extension of time applications.

How is the CIL Charge Calculated?

The CIL charge is calculated in accordance with the CIL Regulations 2010 (as amended) and is charged in pounds per square metre on the gross internal area (GIA) proposed by the development. The applicable CIL rates will be taken from the Islington CIL Charging Schedule and the Mayor of London CIL Charging Schedule. The CIL charge is calculated by multiplying the applicable CIL rate for the development by the proposed gross internal area.

The floorspace of any parts of existing buildings on the site to be demolished or retained as part of the development may be eligible for deduction from the proposed gross internal area. In these cases, the existing floorspace will not be charged and effectively only the net additional floorspace will be charged.

To be eligible for deduction at least part of the existing building must have been in continuous lawful planning use for at least six months in the three years prior to the permission being granted. Existing floorspace of retained parts that will continue as the same use in the proposed development will also be eligible for deduction, even if they have not been in use for the required period of time. However, existing parts that have been abandoned cannot be taken into account when calculating CIL.

An index of inflation will be applied to keep the levy responsive to market conditions using the All-In Tender Price Index of construction costs published by the Building Cost Information Service (BCIS).

CIL Calculator

Applicants can carry out an indicative calculation of the potential Islington and Mayoral CIL charges payable on a development using Islington’s CIL calculator. Please note that the calculator is not a formal assessment of CIL liability. The council will carry out a formal assessment after permission is granted for a CIL liable application and this will be set out in the Liability Notice that will be issued.

Which Developments are Eligible for CIL Relief or Exemption?

A CIL chargeable development may be eligible for relief or exemption from paying CIL. The relief or exemption must be applied for prior to commencement using the forms listed on the CIL Collection Process webpage.

The following types of CIL relief or exemption may apply:

  • Social Housing Relief - developments providing affordable housing will be eligible for relief from CIL.

  • Charitable Relief - developments where the owner is a charitable institution and the development will be used wholly (or mainly) for charitable purposes will be eligible for relief from CIL.

  • Exemption for Residential Extensions and Annexes - people who build extensions or residential annexes to their own home that are over 100sqm will be exempt from the levy, provided that the main dwelling is their principal residence, and they have a material interest in it. Residential extensions under 100 square metres are already exempt from the levy under the above minor development exemption.

  • Exemption for Self-Build Housing - people who build or commission their own home may be exempt from the levy, provided they own the property and occupy it as their principal residence for a minimum of three years after the work is completed.

  • Exemption for minor development - developments proposing less than 100 square metres of new build floorspace will be exempt from the levy. However, where an extension will result in the creation of a new dwelling the development will be CIL chargeable, unless it is eligible for the Exemption for Residential Extensions. The minor development exemption is taken into account at the beginning of the process when the council determines whether a development is CIL chargeable, as set out above.

Islington Council and the Mayor of London do not have a policy for granting discretionary charitable relief or exceptional circumstances relief, and will not accept claims made on this basis.  

Further information on CIL relief and exemptions can be found in the CIL Guidance on the Planning Practice Guidance website.  

Further Information

Guidance on the Community Infrastructure Levy, including information on CIL reliefs and exemptions, and details of how CIL is calculated, can be found on the Planning Practice Guidance website.

Contact us

For further information on the CIL please contact the Developer Contributions team at

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