Smoke and heat alarm requirements in Section 1 of Approved Document B (AD B) are based on the Code of Practice BS 5839-6:2013. It defines ‘Grades’ (the reliability of a system in terms of its power sources) and ‘Categories’ (in which areas smoke or heat alarms are required for detection). The current edition of AD B only calls for alarms in escape routes – effectively Category LD3 – plus heat alarms in kitchens open to circulation areas. It also includes specific recommendations on positioning alarms.
Now, in response to recommendations made by Dame Judith Hackitt following the Grenfell Tower fire, AD B has been redrafted “to improve usability and reduce the risk of misinterpretation”. However, the new Section 1.1 simply states that: “All new dwellings should have a fire detection and fire alarm system, minimum Grade D Category LD3 standard, in accordance with the relevant recommendations of BS 5839-6”, without any further comment. The problem is that Category LD3 falls below the minimum standard in BS 5839-6, invalidating the proposed use of its recommendations alongside the new AD B.
Actually, in BS 5839-6, properties that would require Building Regulation compliance are recommended a minimum Category LD2 (or even LD1 in some cases). Category LD2 means smoke alarms in living rooms, as well as escape routes, and also heat alarms in every kitchen. Furthermore, commentary in BS 5839-6 raises real concerns about the safety of Category LD3. It stresses that: “A Category LD3 system cannot be expected, with any degree of reliability, to protect people who might be involved with the fire at ignition or in its early stages…and might not, therefore, prevent the death or serious injury of occupants in the room where the fire originates”.
In addition, BS 5839-6 recommends an individual risk assessment where a lower than recommended category is applied (such as Category LD3 for properties requiring Building Regulations compliance). Is this really what the Government intends? There are also dangers in omitting heat alarms from kitchens, as over 60% of domestic fires start there. Despite this, the existing AD B specifically requires heat alarms only in kitchens open to circulation areas. But the new draft AD B makes no reference to heat alarms in kitchens at all, effectively resulting in a further reduction in minimum standards.
All of these issues would be resolved if the new AD B simply called for a minimum Category 2 level of smoke and heat protection. This would not only align with BS 5839-6, but also with current Building Regulations guidelines in Scotland and Northern Ireland. After all, installation of sufficient, interconnected mains smoke and heat alarms to provide a straightforward, low-cost early warning is an essential first step in making all housing safer.