The LWF Blog

Facilities Management & Fire Safety – Fire Safety Engineering & the Prescriptive Approach – Part 5

November 15, 2018 1:17 pm

In LWFs blog series for those who work in facilities management or who have an interest in or responsibility for fire safety, we have been looking at the term ‘Fire Safety Engineering’ and what it involves. In part 4 of the series, we began to look at the differences between fire prevention and safety based on prescriptive codes and fire safety engineering. In part 5, we will continue from that point by looking at the common criticisms of prescriptive codes.


Elements of prescriptive codes are arbitrary with some being based on a ‘that sounds reasonable enough’ type of logic. One such example is that of travel distances. The prescriptive distances were compiled with no reference to engineering or scientific reason, it just seemed a reasonable basis on which to require exits to be distributed. However, with developments in design and additional fire prevention and suppression methods being used regularly, such limitations have become less relevant.


Prescriptive limitations are often intended to be applied with an element of flexibility, but have been applied with rigidity meaning, in the case of some building or renovation projects, a vast increase in disruption and unnecessary expenditure has been seen with only small elements of gain from a fire safety point of view.


Architectural building design would be restricted by adhering to prescriptive rules and the lack of constraint offered by fire safety engineering practices allows more creative freedom.


Fundamental problems of fire safety are not always addressed. In addition, prescriptive codes in different areas often do not relate to each other and are considered only in isolation. A fire safety engineered solution is a composite design taking into account all relevant factors together.


Governing bodies have been impressed by these reasons and this has led to a change of approach in terms of building regulations. In England and Wales, a building design team has the choice of whether to adopt the prescriptive codes and standards in Approved Document B or they may adopt the alternative approach of a fire engineered solution. A fire engineered solution may use elements of prescriptive work such as compartmentation, or a prescriptive solution may be added to with the use of sprinklers, for example.


A fire safety engineering solution simply means that it fulfils the functional requirements of legislation without following a prescriptive code of practice.

In part 6 of this series, LWF will continue looking at fire safety engineering. 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 Peter Gyere on 020 8668 8663.


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.


Share this post