Designing for fire safety

Fire and Emergency New Zealand

Designing for fire safety

The purpose of fire safety design in a building is to allow people to escape the building before being overcome by the effects of fire.

The traditional approach

Until 1991 the building code in New Zealand was a prescriptive code that followed a set of rules for designing a building. This was common in many countries where a lot of similarly specific rules had been developed that related to fire safety in buildings. The kinds of provisions that were specified included:

  • the number of emergency exits from a building
  • where the exits must be located
  • signs required at exits
  • systems required to detect fires
  • alarms required to warn people of fire
  • sprinkler systems to extinguish fires
  • building construction materials  which would slow fire growth
  • construction to limit fire spreading from one area to another
  • structural elements to stand up for long enough to get people out and enable firefighters to mount an attack.

A performance-based approach

Since 1991 the  traditional approach to fire safety in building design was replaced with a performance-based approach. The traditional approach was  expressed in the prescriptive approved documents with formed part of the building code. These approved documents are one way of satisfying a building’s performance requirements, but a designer can put forward alternative solutions for approval.

Using an alternative solution allows the designer to design buildings using fire engineering rather than relying on rules. Fire engineering relies on the principles of fire science, human behaviour and risk management. This process requires the designer to think through the following issues:

  • fire ignition growth and spread
  • how people will become aware of a fire and what they might do
  • location of people in the building and their state
  • how quickly people can get out
  • fire development
  • how the smoke and fire might affect people
  • smoke generation and how it could spread
  • how the building materials will respond to the fire.

Considering all these issues allows a fire safety solution to de developed that suits the particular building and its use.