What do the UK Building Regulations say about automatic fire suppression?

Building Regulations are the legal requirements for all new and significantly altered buildings in the UK. They are functional (performance-based), not prescriptive. This means they state what the requirements are, they do not say how these requirements must be met.  Here are some of the requirements, in Schedule B, typically relevant to Automatic water fire suppression systems (AWFSS):

Requirement B1 Means of warning and escape B1. The building shall be designed and constructed so that there are appropriate provisions for the early warning of fire, and appropriate means of escape in case of fire from the building to a place of safety outside the building capable of being safely and effectively used at all material times.’
Requirement B3 Internal fire spread (structure) (1) The building shall be designed and constructed so that, in the event of fire, its stability will be maintained for a reasonable period (2) A wall common to two or more buildings shall be designed and constructed so that it adequately resists the spread of fire between those buildings. For the purposes of this sub-paragraph, a house in a terrace and a semi-detached house are each to be treated as a separate building. (3) Where reasonably necessary to inhibit the spread of fire within the building, measures shall be taken, to an extent appropriate to the size and intended use of the building, comprising either or both of the following— (a) sub-division of the building with fire-resisting construction; (b) installation of suitable automatic fire suppression systems.
Requirement B5 Access and facilities for the fire service (1) The building shall be designed and constructed so as to provide reasonable facilities to assist firefighters in the protection of life. (2) Reasonable provision shall be made within the site of the building to enable fire appliances to gain access to the building.’

Despite suppression only being cited in B3 of Schedule B, it is recommended in Approved Document B and BS 9991 as a way to improve the means of escape for occupants. It can be used to contain the fire within the room of origin and also to provide a 'compensatory measure' when other building features do not meet one of the functional building requirements, as explained in 4.2 of BS 9991.

‘Automatic water fire suppression system (AWFSS) The installation of an AWFSS can offer designers considerable flexibility. An AWFSS controls a fire to a small size, reducing the production of smoke and toxic gases and preventing the fire from spreading beyond the room or dwelling of origin. This means that there can be flexibility achieved in the design of the building.’

Regulation 7 provides guidance on materials and workmanship, i.e. the use of the appropriate materials for construction and how those who are working on the building must behave in a workmanlike manner.

Approved Document B outlines one method of meeting the functional requirements of the building regulations.

Disclaimer: This information is not intended to be a comprehensive guide to all of the aspects of the building regulations but rather a useful source of background information. Whilst every care has been taken to ensure that the contents of this document are correct at the time of publication, it should never be used as any form of substitution for the guidance documents. Plumis shall be under no liability whatsoever in respect to the contents of this document. It should be noted that there may be specific additional requirements dependent upon local authority building regulations and/or fire authority.