Performance Based Design Brings Better Engineering Into Fire Protection (Part-I)

A case study on how to reduce the high costs of fire-protection

A major manufacturing company in the US decided to design fire-protection features for its large building. To safely evacuate occupants of the building during a fire, the local body, Authority Having Jurisdiction (AHJ) recommended automatic smoke and heat vents in the building roof and also on the roof of enclosed corridors. Construction of these vents would incur huge costs besides operational and maintenance costs. The recommendations of AHJ on fire and life safety did not convince the company. Therefore, the company decided to try a “performance based approach” to design fire-protection equipment.

New companies should look out for cost-effective methods in building construction and in business operations since global business operations are becoming more and more competitive. The non-productive costs including fire-protection equipment should be substantiated. The reduction in fire risk is not in proportion with the high cost of designing fire-protection requirements as evaluated by “prescriptive approach”.

Performance-based design and analysis methods are used to evaluate the investment in fire protection features. The evaluations are based on reasonably expected fire consequences and risks. This approach when applied to manufacturing buildings and power-generating facilities can avert installation of expensive fire protection equipment that is not justified strategically.

Prescriptive approach to evaluate fire safety standards is an old concept, which is based on judgement, experience and history. Experts have approved these standards individually to provide an acceptable level of safety. However, the results of the safety standards are not quantifiable either in terms of the safety level or the cost-effectiveness in this approach.

A comparative analysis of performance and prescriptive approach revealed that:

• Performance-based fire standards offer flexible and creative solutions based on scientific and engineering principles. These solutions are more suitable to complex and unusual shaped structures. Due to their flexibility, these solutions while preserving social and economic values optimise on expenditure and consumption of resources. In this approach the consequences and fire risks can be measured and compared with the costs required to implement various alternatives. Compliance with the approach requires engineering evaluations

• Prescriptive fire protection standards offer rigid solutions, based on the collective knowledge of those that developed the standards for general use.  In this approach the objectives are developed for a particular situation. Compliance with the approach requires technical comparison in addition to well-defined requirements.

Performance-based fire standards have been in use in the UK, Australia and New Zealand since 1990s. Only after the National Fire Protection Association (NFPA) in the US has agreed to develop these standards in 1995, this approach was introduced in the US. The 2000 edition of the NFPA “Life Safety Code” has set a standard that all the organisations should incorporate a performance-based approach to fire and life safety.

The objective of the Society of Fire Protection Engineers (SFPE) is to capture the best practices in the fire-protection engineering community. SFPE has defined fire-protection practices in terms of performance-based design.

A case study on how the use of performance–based approach in a large industrial facility in the US helps to ensure cost-effective fire protection is discussed in the next article.

Related Reading
Quantifying risk, Holmes, W., Consulting–Specifying Engineer.