Glossary
Community Infrastructure Levy
The Community Infrastructure Levy (CIL) is a charge some councils levy on new floorspace to help fund local infrastructure. Householder extensions can be caught if they create chargeable floorspace above set thresholds.
Self-build and residential extension reliefs may apply if you serve the right notices on time. Rules and rates are set in each charging authority’s schedule.
CIL is primarily an England (and limited Wales) tool. Scotland and Northern Ireland use different infrastructure-charging approaches.
Official source: Community Infrastructure Levy (GOV.UK). Checked 27 October 2026.