Buro Happold Specialist Consulting

Fire Engineering Design and Risk Assessment

Application of BS 9999 to Supermarkets

12th November 2009

Andy.Nicholson@BuroHappold.com

Agenda

• BS 9999 time line

• Designing for means of escape

• The BS 9999 process

• Case study

• Fire engineering

• Fire safety management

• Summary

1998 2000 2002 2004 201020082006

Work started in 1998- Development of the risk profile approach

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Public comments received November 2001

Task Group convened to review

DD 9999 published

BS 9999

published

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BS 9999 – History

BS 5588

withdrawn

Designing for means of escape

The general approach

•Height and use of the building determines fire measures

• ~2.5m notional escape time prescribed through 5mm/person

The advanced approach

• What people are doing and how quickly a fire can grow

• Minimum fire safety measures prescribed

• Additional measures reduce risk and increase time and this transpires as distances and widths

Designing for means of escape

Fire safety engineering

•Demonstrate people can escape safety before times foruntenable conditions

Designing for means of escape

1. Establish predominant occupant characteristic

Retail => Occupants are awake & unfamiliar

=> Occupant Characteristic ‘B’

2. Establish fire growth rate

Retail => Fast fire growth

=> Fire Category ‘3’

3. Combine to produce the ‘Risk Profile’

Retail => Risk Category is ‘B’ & Fire Category is ‘3’

=> Risk Profile is ‘B3’

4. Sprinklers reduce the risk profile from B3 to B2

The BS 9999 process

Managing fire safety

•Management is incorporated into design process

•Ties in well with Regulatory Reform Order

•No other impact on the design

•Minimum levels outlined

• Level of management L2 or L1

• Alarm & detection L2 or M

• Emergency Lighting

• Emergency signage

• Doors and final exits

• Lifts

• Mechanical ventilation systems

• Refuse

• B3 16m and 40m travel distance and 7mm/person stair width

• B2 20m and 50m travel distance and 4.8mm/person stair width

Minimum package of fire safety measures

Additional measures

• Increase travel distance, and decrease exit & stair widths

• Better automatic alarm & detection allows 15% variation

• High ceilings allow percentage variation depending on height

• Multiple ‘additional’ measures can be added

• BS 9999 recommends an upper limit for variations

• What type of buildings have these additional measures as part of their base build requirements?

Case study

Travel distance – ADB v’s BS 9999

Travel distance – Reduce risk profile

Travel Distance – increase fire protection measures

Exit width and final layout

ADB 5mm/person = 2.5 minutes

BS 9999 3.6mm/person = 3.5 minutes

Fire engineering and fire safety management

• Use of travelators as a principal escape route

• Demonstrate tenability from products of combustion

• Supports the psychology of escape

• Better escape for people with disabilities

• Reduces complexity with management

Summary

• Risk profile is a more advanced qualitative risk assessment

• Supermarkets more onerous than ADB as a result of risk profile

• Greater flexibility - Benefits achieved for increasing fire safety provisions

• 15% benefit for alarm and detection is subjective

• Encourages the use of sprinklers

• The process should be used in its entirety

• Ties fire safety management into the design process supporting the RRO and closing the circle of fire safety