Potentially, but a change of use for a barn to residential use should not result in CIL liability as long as the barns are permanent usable buildings in lawful use. To be usable, such buildings should be weather tight with four walls, floor and a roof. To be exempt from CIL the barn should have been in lawful use for a continuous 6 months out of the three years prior to planning permission first permitting development. However, any additional new build floor space would be liable for CIL.