When you apply for planning permission you’ll need to see if you have to pay the Community infrastructure levy (CIL)
It applies to most new developments (new buildings or extensions) which involve creating 100m2 or more of gross internal floor space.
Developments that create one or more dwellings will be chargeable, even where the additional floor space is below 100m2
Find out if you need to pay CIL on the Planning Portal website.