The LWF Blog

Fire Safety Engineering for Design – Building Types & Fire Load – Part 27

May 4, 2021 11:46 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 26, LWF considered buildings with special features, as well as life safety and property protection. In part 27, we look at what fire precautions must be taken when a building is being constructed and discuss risk profiles.

It is important that the design team and building owner address the issue of fire precautions while a building is under construction. The fire loads during construction can be greater than in the completed building. Particular attention should be paid when the building is constructed from combustible materials.

If construction is taking place in part of an operational building, there can be severe consequences if the additional fire risk is not assessed and mitigated.

The Fire Protection Association in the UK produced a code in 2015 ‘Fire Prevention on Construction Sites’ which is a code of practice on the protection from fire of construction sites and buildings undergoing renovation.

Risk Profiles

It is necessary to assess the risk to persons from fire in different buildings and although the previously discussed purpose group approach can be used, it may be beneficial to adopt the risk profile approach, as an alternative.

The risk to which a building occupant is exposed is a combination of certain factors; the occupancy group and the likely fire development. The simplest examples are common sense – it is a greater risk to have building occupants in a sleeping state during a fire emergency, for example in a hotel, than it would be in a school, where the occupants would be awake and familiar with the building.

BS 9999:2017 – Fire safety in the design, management and use of buildings – Code of practice gives detail on risk profiling on the basis of dividing occupancy into seven life risk categories and fire development into four established growth scenarios. The lower risk categories allow more flexibility in terms of building design.

BS 9999 does not address certain type of occupancies, such as transport infrastructure. Where an occupancy cannot be covered by a specific code of practice, the risk profile should be individually assessed and a performance-based approach applied.

It should be noted that after construction of a building, change of use can constitute change of risk profile and the potential impact should be identified and considered at design stage.

In part 28 of LWF’s series on fire engineering, we will look at designing the fire precautions for a building. 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.