The LWF Blog

Fire Safety Engineering for Design – Designing Fire Precautions – Part 36

July 5, 2021 11:02 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 35, LWF looked at fire precautions in residential institutional buildings. In part 36, we will discuss fire precautions in office buildings and how this purpose group differs in its requirements.

When considering fire precautions and fire safety design for office buildings, there are certain factors which should be considered. The first is that while the primary motivation must be life safety, office buildings have a history of low incidences of fire and also, of low loss of life due to fire.

The second is that commonly, there is a need to maximise design flexibility, and finally, the fire-load is likely to be in line with consistent patterns and is easily understood.

The fact that life safety risk is low enables flexibility in the design of the building and in the fire safety solution created alongside that design. However, it is also true that business and contents protection and the avoidance of business interruption take on an increased importance in buildings of this type.

There has historically been an issue in office buildings where, in the early stages of a fire, smoke can spread through the ventilation and air conditioning ductwork. While this has not caused any fire casualties historically, it should be avoided in any good design. Approved Document B and BS 9999 both advise that smoke movement in these systems can be avoided by using smoke detector operated fire/smoke dampers.

In an office building, commonly the building occupants are employees and so have a good understanding of building layout. The main emphasis on controls relates to means of escape. An atrium may be added without vastly increasing the risk, provided reasonable additional provisions are made to facilitate safety. BS 9999 Annex C gives further information on the fire safety design required for inclusion of atria.

It should be noted that Approved Document B states the guidance given on atria in BS 5588-7 only applies where an atrium traverses compartment floors. BS 9999 recommends the guidance is relevant where a void traverses any floor, whether a compartment floor or not.

In part 37 of LWF’s series on fire engineering, we will look at fire precautions in shops and other commercial premises. 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.

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