Standard Downlight – 150mm x 150mm fitting with 50mm clearance to surrounding ceiling insulation
IC Rated – Ceiling can be abutting the downlight fixture but not placed over the top
IC4/ICF Rated – Insulation can be laid all around the fitting and over the top so there is no reduction to ceiling insulation
Where the downlight information is unknown, worst-case scenario will be used which is Standard (unsealed)