The LWF Blog

Fire Safety Engineering for Design – Designing Fire Precautions – Part 35

June 28, 2021 10:47 am

LWF’s Fire Safety Engineering blog series is written for Architects, building designers and others in the construction industry to highlight and promote discussion on all topics around fire engineering. In part 34, LWF discussed fire precautions in residential institutional buildings, including the use of water suppression protection. In part 35, we continue to look at fire precautions in residential institutional buildings.

The current legislation covering fire precautions in existing buildings in the residential institutional building category was comprised of lessons learned as a result of significant fires causing fatalities. The fires took place in establishments within group (b), which includes hotels and boarding houses. The statutory controls for buildings falling into group (b) are less onerous than for those within group (a) and focus largely on compartmentation and fire detection. The provisions for means of escape are more commonly conventional, with the advantage that often, normal circulation routes are also those leading to emergency exits. Emergency lighting may be required along the escape route.

The reasons for this type of emphasis on group (b) buildings is that the main aim is simply to promptly warn building occupants of a fire and facilitate a speedy evacuation to a place of safety. The law is not concerned with the fate of the premises or its contents, aside from the potential for fire to pass from one occupancy to the next. It may be that an insurer or the building owner requires additional fire protection measures in order to protect their investment. The situation with group (a) premises is significantly more loaded, because these are buildings intended to house people with infirmities and includes healthcare premises.

BS 9999 Annex C contains information for those premises in group (b) that may incorporate an atrium, which would require additional controls in order to offset the risks caused by the loss of compartmentation as passive fire protection. The additional controls are likely to include sprinkler systems and smoke control systems to help ensure tenable conditions for the evacuation of building occupants. The standard includes prescriptive guidance for occupancies including atria, but also allows for an engineered approach.

In part 36 of LWF’s series on fire engineering, we will begin to look at fire precautions in office buildings and how that purpose group differs in its requirements. In the meantime, if you have any questions about this blog, or wish to discuss your own project with one of our fire engineers, please contact us.

Lawrence Webster Forrest has been working with their clients for over 25 years to produce innovative and exciting building projects. If you would like further information on how LWF and fire strategies could assist you, please contact the LWF office on 0800 410 1130.

While care has been taken to ensure that information contained in LWF’s publications is true and correct at the time of publication, changes in circumstances after the time of publication may impact on the accuracy of this information.