The LWF Blog

Fire Engineering Design and Risk Assessment – Ultra High-Rise Buildings – Part 55

August 19, 2019 12:39 pm

In LWF’s Fire Engineering blog series for Architects and others in the building design business, we have been discussing firefighting and the relevant provisions that should be made for those activities at building design stage. In part 54, we began to look at ventilation systems which are designed to remove smoke and heat from an area to maintain tenability. In part 55, we will continue talking about ventilation before moving on to consider ultra high-rise buildings.

Ventilation Systems

When considering if a single-storey building requires ventilation, many variables should be taken into account, such as the objectives of firefighting activities, the type and amount of goods held within the premises, the projected rate of smoke production, the potential size of the smoke reservoir created by the building volume and the timeline for the Fire Service attending and carrying out their duties.

Where it is necessary to include ventilation in spaces in large buildings, underground car parks, any underground storey or basement level or firefighting shafts, the following three processes should be undertaken:

1) Determine the functional requirements for the ventilation in the given space.
2) Calculate the height of the clear layers and smoke temperatures as a function of time.
3) Work out the circumstances which will fulfil the requirements.

Ultra High-Rise Buildings

The proliferation of high-rise buildings in cities and metropolitan areas in order to afford business and residential accommodation has brought its own challenges in terms of fire safe design. The definition of a high-rise building can vary from floor heights of 12 m up to 45 m.
There are also buildings throughout the world which are considered ultra high-rise and they allow us to consider the fire safety aspects related to these builds in terms of access to the building for firefighters and rescue.

With some of the tallest buildings in the world having over 2000 steps in staircases from top to bottom, the equivalent of a mile covered, it is not possible for occupants at all levels to simply evacuate the building via the stairs as in a normal evacuation situation. Even if each occupant were physically able to do it (and nobody could guarantee that they would be) the time taken would be excessive and therefore not a viable fire safety option.

In part 56 of this series, LWF will look at some of the innovative fire safety solutions employed by the designers of ultra high-rise buildings. 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 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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