The LWF Blog

Fire Safety Engineering for Design – Building Types & Fire Precautions – Part 20

March 15, 2021 11:57 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 19, LWF looked at the fire engineering implications of a building’s depth below ground. In part 20, we will see how an increased building area impacts fire engineering design.

A building with a large building area is one where the floor area is greater than average. Such buildings come with certain implications affecting a fire engineered design.

• Greater fire loads
• Increased horizontal travel distances, through which occupants may have to travel to evacuate
• Additional firefighting challenges, a greater distance to a point of safety, larger areas to search and being unable to reach all areas of a floor plate from outside the building.

Where the maximum permitted travel distance is adhered to, this will be a determining factor of the maximum possible floor area. However, where extended travel distances are preferred for the design, smoke control methods and other active and passive fire protection measures may be required.

Internal protected corridors may be one method employed to enable the safe passage of building occupants in a fire situation.

The use of compartmentation and sub-compartmentation can divide fire loads, or active fire protection methods can also be used as an alternative.

Although there is often a fire safe alternative in design to the maximum permitted travel distance, allowing buildings with an extended floor area, there is another limitation which cannot be so easily remedied. Firefighting hose lengths and the practical limit of laying out hoses usually defines the maximum distance for design purposes.

Recently, the construction of commercial use buildings, sometimes known as ‘landscrapers’ involve a floor area many times larger than conventional new developments, which has led to them not being adequately addressed by the current guidance documents in terms of designation of fire size and type.

In part 21 of LWF’s series on fire engineering, we will continue looking at those buildings with a very large floor area. 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.