VCONST13770 | Building materials - Note 22 and Note 23: electrical and gas appliances: burglar alarms, and so on
From HM Revenue & Customs · VAT Construction
Appliances are not excluded from the definition of ‘building materials’ when they are:
burglar alarms
personal alarms
fire alarms
fire safety equipment
or
appliances designed solely for the purpose of enabling aid to be summoned in an emergency.
Note: Other electrical appliances that are used as part of a security system are excluded from being ‘building materials’, such as closed circuit television (CCTV) cameras.