Hi all,   I’m in the process of building a new home for my family.    Planning permission was granted for a two-storey house and the build commenced 5 months ago.    We have just decided that we want to go bigger and add a basement underneath the patio that is on sloped land so will open up on to the garden.   I have been advised that this will require a full planning application and could put our CIL exemption at risk as the CIL is attached to a planning applic