Boilers and heating
Circuits and Electrics
Ground source heat pump (internal unit)
Micro-Combined Heat and Power / Biomass
Unimproved loft space
Building Regulations do not normally apply for works to a ceiling unless more than 25 per cent is being replaced below a cold loft space or flat roof. In which case Building Regulations will apply and the thermal insulation of that ceiling would normally have to be improved.