As building design gets more innovative, the industry needs to come up with alternative fire safety strategies by making full use of expert engineering analysis rather than relying on government-issued guidance.

The industry’s prescriptive approach is reflected in the reaction to failures in fire safety. In the wake of major fires, there’s a clamour on social media focusing on one form of protection or another – ‘If only the building had automatic sprinklers, or an aspirating detection system, or had been constructed of non-combustible materials…’.

The advocates for one particular system may be right from their own narrow analysis, but long before those determinations can be made – either before a project starts or during an investigation post-fire – a series of broader questions needs to be asked. These include:

• What are the fire safety objectives?
• What are the acceptance criteria to determine if these objectives are met?
• What hazards are present and what risks do they present?
• Do those risks need to be mitigated, or are they tolerable to the stakeholders?

If risk analysis indicates mitigation is needed, the designer needs to ask not just what form mitigation should take, but also how far should it go with regard to:

• Compliance with the minimum set out in codes and standards?
• Increased measures beyond code compliance to take account of corporate risk management goals or insurance risk assessments?
• An innovative fire-engineered solution?

However, even when fire engineers propose innovative alternatives that don’t conform to government-issued guidance, they usually benchmark their designs against the same prescriptive guidance rather than developing their own acceptance criteria through engineering analysis.

True value of fire safety guidance?

However, this unquestioning adherence to guidance is challengeable. Existing guidance does not define the level of safety to be achieved or distinguish between protection for different stakeholders, such as building occupants, fire-fighters, and the property itself.

It usually is assumed that guidance and standards always provide the desired level of safety. While guidance will normally provide an adequate safety level, that is not necessarily the case. Like all standards and guidance, they are backward-looking documents, developed in the past, based on technology, knowledge and experience at the time they were published. In fact, many such documents have sections that are unchanged from when they were first issued, perhaps 40 or more years ago. It is often only after major fires, such as Piper Alpha in the North Sea, Tamweel Tower in the UAE and Grenfell Tower in London, that guidance or standards are questioned closely.

This begs the questions: Is the guidance there because it is still valid? Is it still in use because no one wished to question its validity, or was it simply assumed to be valid? Considering how the fire engineering profession can respond, there is the issue of the fire engineering professional’s role, and whether more can be done to apply the knowledge and experience developed by the profession over the last five decades, moving to a framework where fire safety design from first principles is the norm for complex buildings, rather than adopting a code-compliant approach.

However, a lot of work would need to be done to gain acceptance for this approach, when existing, relatively simple fire strategies face difficulties in gaining approval.

A lack of expertise in local authority building control can cause difficulties in getting a fire-engineered design through regulatory approval, and clients don’t want, or can’t afford, project delays. But can we afford to continue building complex structures without clearly defining our fire safety objectives in a measurable way?

Design & verification

The challenges were highlighted in a research, where Professor Brian Meacham¹ found wide variations in the practice and fire engineering capabilities of local authority verifiers. “It appears that resources are lacking for the comprehensive review of ‘significant’ designs,” he noted. Also, there was “a wide range of competency in the fire engineering community”, and a limited number of fire engineers available for independent third-party review².

While the number of fire-engineered solutions requiring verification has increased in recent years, Professor Meacham also argued that limited supply and competence were curbing the industry’s ability to take advantages of the flexibility in the building code system, calling for “nationally consistent guidance” on the qualifications, competencies and experience required for verifying both minor and significant deviations from fire safety guidelines.

In the wake of major fires, there’s a clamour on social media focusing on one form of protection or another – ‘If only the building had automatic sprinklers, or an aspirating detection system, or had been constructed of non-combustible materials…’. The advocates for one particular system may be right from their own narrow analysis, but long before those determinations can be made – either before a project starts or during an investigation post-fire– a series of broader questions needs to be asked.

Al Brown, Director