BS 9999: Fire Safety in Non-Residential Buildings

BS 9999 is the British Standard for fire safety in the design, management and use of non-residential buildings. It covers offices, retail premises, warehouses, industrial buildings, places of assembly, hotels, and other non-domestic occupancies. Where BS 9991 covers residential buildings, BS 9999 covers everything else.

The current published edition is BS 9999:2017. A revision is under development at BSI but has not yet been published. The related residential standard BS 9991:2024 has been updated, and some of its smoke ventilation changes (notably the 1000 Pa damper test pressure under BS EN 12101-8) are relevant to non-residential specifications written to BS 9999.

Scope

BS 9999 covers:

• Design of means of escape for non-residential occupancies
• Smoke ventilation and smoke control strategies
• Compartmentation and structural fire protection
• Fire detection, alarm, and suppression systems
• Fire service access, facilities, and information
• Ongoing management and maintenance obligations

As with BS 9991, it is a guidance standard - providing a framework for demonstrating compliance with the Building Regulations rather than imposing absolute prescriptive rules. A building designed in accordance with BS 9999 can demonstrate compliance with the functional requirements of Approved Document B (or equivalent devolved legislation).

Relationship to BS EN 12101

BS 9999 references the BS EN 12101 series for all smoke ventilation and smoke control product requirements:

Damper Test Pressure: A Note on BS 9991:2024

BS 9991:2024 (the residential equivalent of BS 9999) made a substantive change to the reference test pressure for smoke control damper leakage classification under BS EN 12101-8, moving from 500 Pa to 1000 Pa. BS 9999:2017 has not been updated to mirror this change, but non-residential damper specifications often align with the same test pressure basis. Practical implications for BS 9999 work:

• Products certified at 500 Pa may not achieve the same classification at 1000 Pa
• Damper schedules should confirm the test pressure basis used
• Building control may query the test pressure basis when reviewing schedules
• A future revision of BS 9999 is in development at BSI and may align with the 1000 Pa basis

See BS EN 12101-8 for the full damper leakage classification system.

Smoke Control Strategies in Non-Residential Buildings

Non-residential buildings present a wider range of smoke control challenges than residential - from large open-plan floors to atria, car parks, covered malls, and industrial spaces. BS 9999 addresses:

Atria and Large Open Spaces

Natural or powered smoke extract from an atrium smoke reservoir, bounded by smoke barriers or smoke curtains, with clear layer calculations to maintain a tenable environment for evacuation.

Car Parks

Mechanical ventilation systems designed to dilute and extract smoke and combustion products - typically using impulse fans combined with smoke extract fans meeting BS EN 12101-3.

Corridors and Escape Routes

Smoke control to protect escape routes, using AOV roof vents or mechanical extract to maintain a clear layer above the evacuation route. The non-residential stair target is 1.0 m² aerodynamic free area (Aa): use the Free Area Calculator to verify compliance.

High-Rise and Complex Buildings

Pressure differential systems protecting stairwells and refuges, often combined with mechanical extract on fire floors.

Fire Risk Assessment and Management

BS 9999 places significant emphasis on ongoing management, requiring:

• A suitable and sufficient fire risk assessment, reviewed regularly
• Maintenance of all fire safety systems including smoke ventilation
• Records available to building control, fire service, and responsible person
• Competent persons carrying out all inspection and testing

For higher-risk or complex buildings, the Building Safety Act 2022 introduces additional accountability requirements. See Approved Document B for the regulatory context.

See also: Free Area Calculator · Smoke Ventilation Glossary

Related Standards

• BS 9991 - The equivalent standard for residential buildings
• BS 7346 - Components for smoke and heat control systems
• BS EN 12101 - Overview - The product standard family referenced throughout BS 9999
• Approved Document B & Building Safety Act - UK regulatory framework

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