Scottish Government

standard
2.15
mandatory

Every building to which this standard applies must be designed and constructed in such a way that, in the event of an outbreak of fire within the building, fire and smoke will be inhibited from spreading through the building by the operation of an automatic life safety fire suppression system.

Limitation

This standard applies only to a building which:-

a. is an enclosed shopping centre;

b. is a residential care building

c. is a domestic building in which there is a floor at a height of more than 18 metres from the ground; or

d. forms part of a sheltered housing complex.

2.15.0 Introduction

The term automatic life safety fire suppression system includes life safety sprinklers, but also provides the opportunity for designers to propose other systems which may be just as effective. The key characteristics of the system are:

• it must be automatic and not require people to initiate its activation,
• it must be designed primarily to protect lives, rather than property, this means it will normally be fitted with quick response sprinkler heads.
• it must be a fire suppression system, one designed specifically to deal with fires rather than other hazards.

High rise buildings

Due to the increased risk in high buildings with a storey height exceeding

18 m, additional guidance is provided in Annex 2.A.

Conversions

In the case of conversions, as specified in Regulation 4, the building as converted must meet the requirements of this standard (Regulation 12).

2.15.1 Automatic life safety fire suppression systems

Automatic life safety fire suppression systems are required in two categories of domestic buildings, dwellings with a floor at a height of more than 18 metres from the ground and dwellings which form part of a sheltered housing complex.

Water supply

For a suppression system to be effective it is essential that there is an appropriate and adequate water supply. Therefore designers need to discuss with Scottish Water what supply is likely to be available and what pressure can be expected. It is recognised that pressures will vary during the day, over the year and perhaps in future years. Therefore it is imperative that the system is designed on the basis of what the minimum pressure is likely to be.

Maintenance

Auto-suppression systems require maintenance and it is essential that systems once installed are regularly checked and maintained. It may be that the requirement to provide such maintenance is made a legal obligation on the owner by the addition of a Continuing Requirement when the completion certificate is accepted by the verifier (under section 22 of the Building (Scotland) Act 2003). Failure to comply with such a Continuing Requirement could lead to enforcement proceeding being taken and might mean that the premises could not be legally occupied.

Flow rates

2.15.2 Sheltered houses

A dwelling forming the whole or part of a sheltered housing complex should have an automatic life safety fire suppression system designed and installed to DD 251: 2000. The system flow rate should be capable of providing at least 60 litres per minute through any single sprinkler and at least 42 litres per minute through each of 3 sprinklers operating simultaneously.

Components

Components of the system should be as specified and tested in accordance with DD 252: 2002. Sprinkler heads should be 'quick response type' with a response time index (RTI) of 50 (m.s) ^1/2 and a conductivity factor (c) of not more than 1 (m/s) ². Sprinkler heads which are not 'quick response type' (e.g. concealed or recessed pattern sprinkler heads) should only be used with the approval of the verifier.

Alternatives

There are many alternative or innovative fire suppression systems available including fresh water sprinkler systems, mist or fog systems. Verifiers should satisfy themselves that such systems have been designed and tested for use in residential buildings and are fit for their intended purpose (see Section 0).

2.15.3 Domestic buildings in which there is a floor at a height of more than 18 metres from the ground

A domestic building in which there is a floor at a height of more than 18 metres from the ground should have an automatic life safety fire suppression system designed and installed in accordance with guidance set out in Annex 2.A.

Annex 2.A Additional guidance for buildings with any storey at a height of more than 18m

2.A.0 Introduction
2.A.2 Separation
2.A.3 Structural protection
2.A.4 Cavities
2.A.6 Spread to adjoining buildings
2.A.7 Spread on external walls
2.A.10 Escape lighting
2.A.14 Fire service facilities
2.A.15 Automatic life safety fire suppression systems

Annex 2.A

Additional guidance for buildings with any storey at a height of more than 18 m

High rise flats

2.A.0 Introduction

Occupants of high rise flats or maisonettes may not attempt to evacuate the building immediately. Initially they may not be aware that there is a fire in progress or, if there is a fire in progress, they may not immediately perceive themselves to be at risk. Due to the increased hazards associated with fires in high rise buildings both to the occupants of the building and to fire fighters, additional active and passive fire protection should be provided. Additional structural fire protection is necessary with increased height and automatic life safety fire suppression systems should be installed within the flats or maisonettes.

Additional recommendations are also provided for separation, cavities, spread to adjoining buildings, spread on external walls, escape lighting, and fire service facilities. To link them directly with the standards, they have been numbered in the same manner.

Flow rates

2.A.15 Automatic life safety fire suppression systems

Flats and maisonettes should have an automatic life safety fire suppression system designed and installed to DD 251: 2000 however the system flow rate should be capable of providing at least 60 litres per minute through any single sprinkler and at least 42 litres per minute through each of 3 sprinklers operating simultaneously.

In addition to the recommendations contained in DD251: 2000 the sprinkler protection should also be provided in:

• roof spaces; and
• ceiling voids between a floor and a ceiling where the cavity is more than 800 mm high.

Due to the high degree of fire separation between dwellings, it may not be necessary nor is it common practice to evacuate high rise domestic buildings in their entirety during the outbreak of a fire. For this reason, automatic life safety fire suppression systems do not need to be installed in common spaces such as stairs, corridors, landings or communal facilities. On arrival, the fire service will assess the need for a complete or a partial evacuation of the building.

Components

Components of the system should be as specified and tested in accordance with DD 252: 2002. Sprinkler heads should be 'quick response type' with a response time index (RTI) of 50 (m.s) ^1/2 and a conductivity factor (c) of not more than 1 (m/s) ². Sprinkler heads which are not 'quick response type' (e.g. concealed or recessed pattern sprinkler heads) should only be used with the approval of the verifier.

Alternatives

There are many alternative or innovative fire suppression systems available including fresh water sprinkler systems, mist or fog systems. Verifiers should satisfy themselves that such systems have been designed and tested for use in residential buildings and are fit for their intended purpose (see Section 0).