Whats the script with the changes? My sister is planning on starting up childminding from her house but she needs to update her smoke detectors. But with it being a childminding business as well as a dwelling whats the rules these days? Do all the smoke detectors need to be mains supplied with battery back up as well as being interlinked wirelessly? Also do you have to supply from an independent circuit rather than piggy back off a light? Is it every room bar the bedrooms and bathroom that need detectors and heat detection in the kitchen?