The LWF Blog

Fire Safety Engineering for Design – Designing Fire Precautions – Part 31

June 7, 2021 11:08 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 30, LWF began to discuss the implications of classification by purpose group and how fire precautions are designed. In part 31, we look at the design of fire precautions for domestic dwellings.

The building designations referred to are the types of building used in Table D1 of Approved Document B and Table 4.3.4 of BS 9999.

Low-rise dwellings are subject to minimal controls for fire precautions, most of which relate to the separation of dwellings from each other in order to control the potential for fire spread and smoke detection. One exception to this is houses of multiple occupation which, even when low-rise, are subject to additional requirements.

Individual dwellings with a habitable storey above 4.5 m and 7.5 m are subject to further control by the need for a protected fire escape in buildings where there is not an alternative exit provided to the main exit. In addition, escape windows and an automatic fire suppression system should be provided.

Information on fire detection and fire alarm systems for use in a wide range of residential buildings can be found in Approved Document B  and BS 5389-6.

Fire safety engineered practices can be useful when working on an unconventional building, such as one where protected escape routes are compromised by an open-plan layout. Some of the solutions used to offset the loss of a protected escape route could be water suppression systems or smoke control systems. In addition, a fire engineered solution may be used when a building is undergoing refurbishment or significant alteration.

In blocks of flats or where dwellings are closely situated, such as with maisonettes, a ‘stay put’ policy strategy is commonly implemented. This means that only the flat of fire origin would evacuate the building and the remainder of the dwellings remain inside. This approach requires significant controls in relation to horizontal and vertical separation (compartmentation) in order to contain the fire within the original dwelling and stop it spreading to others. The original design and provision must be maintained as intended to ensure the separation continues to be functional.

In part 32 of LWF’s series on fire engineering, we will continue to look at the fire precautions used in domestic dwellings, with more information about fire safety in 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.

NOTE: The next blog in this series was published out of sequence, as a result, you can click here to read.

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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