The practice of fire engineering in New Zealand has now some 17 years of experience operating under a performance-based building code. The industry emerged as a result of a radical change in building regulations in 1991, when there was a change from a heavily prescriptive regime to a performance-based set of rules almost overnight. Performance-based fire engineering was embraced as a new way of producing innovative designs.

The industry has matured over the years from a naive start when in its infancy and has gone through some painful learning experiences. Fire engineering is still not a fully mature industry. There are still some significant challenges to be overcome as the practice of fire engineering settles into a structure and method of operating that is universally accepted by all the stakeholders.

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HISTORY

To understand the current state of fire engineering in NZ, it is necessary to first understand the history of the underlying legislation and building regulations that govern the construction and building industry in NZ. Prior to 1991, NZ operated under a fragmented set of building controls that were made up of a combination of government (national) and local authority (regional) regulations, all of which were based on prescriptive requirements.

In 1991, the NZ Building Act¹ was passed that created a uniform, performance-based building code throughout the country. It was administered by the local territorial authorities with regulations developed by a quasi-governmental Building Industry Authority (BIA). The performance-based building code was accompanied by a set of prescriptive, deemed-to-comply documents known as the "Acceptable Solutions". The Building Act was intended to cover all building regulations in one piece of legislation and indeed included a clause to the effect that no authority could require a building to be constructed to a standard that exceeded the building code.

The intention was to deliver an environment that permitted innovative design of buildings while ensuring that basic code requirements were met.

In most areas of the building code, the Acceptable Solutions were prescriptive and based on generic information applicable to most buildings, but in the case of the fire safety acceptable solutions, the introduction stated:

"1.1.1 This acceptable solution is one way, but not the only way, of satisfying the New Zealand Building Code (NZBC) provisions for fire safety in buildings.

1.1.2 The methods given are particularly appropriate for simple, low-rise buildings. However, for individual buildings, alternative solutions developed from specific fire engineering design could produce more economical results."

However, the documents went on to give prescriptive requirements for all possible buildings. Although they were intended as a 'cookbook' set of documents that could be used by anyone for a simple building, they also required specific design in some circumstances but were silent on who could carry out the specific design. There was no requirement for any minimum level of qualification or competence to undertake a specific design.

Indeed, there is no protection on the title 'fire engineer' in New Zealand. There is nothing to stop anyone from calling themselves a 'fire engineer' and carrying out fire safety designs. The only protection (one not relating specifically to fire engineering) is on the status of Chartered Professional Engineer (CPEng), for which one is required to undergo a five-yearly competence assessment carried out under the auspices of the Institution of Professional Engineers NZ (IPENZ).

THE EARLY YEARS

In the years that followed the initial publication of the Acceptable Solutions, it became common for fire safety designs to utilize portions of the Acceptable Solutions combined with departures justified by anything from simple opinion to calculations. Providing the territorial authority was satisfied with the justification, a building consent could be granted and the building constructed. Some consent authorities requested an independent peer review of the design, but there was no mandatory process for checking of fire safety (or any other building code feature, for that matter).

The fire safety design was usually articulated as a 'fire report', which was often a brief document that included a mixture of analysis to show how the building complied with the building code, combined with a summary of requirements that the architect or other designers had to include into their respective designs. In many cases, the fire report was not commissioned or prepared until after the majority of the building design had been completed, so the fire engineer was under pressure to justify that the design complied with the building code. Alternatively, it was not uncommon for preliminary fire reports to be produced early in the design process and the fire engineer not consulted further. There was no mechanism in the process for ensuring that the design intent was fully implemented in the final construction.

Where interpretations were required, the BIA was consulted and determinations issued. Despite objections from many of the original authors of the Acceptable Solutions, the determinations referenced the Acceptable Solutions as a benchmark or minimum standard, rather than a more conservative design solution as they were originally intended. The principle that specific fire engineering design could produce more economic solutions has been pushed aside.

Alongside the Building Act, there is a separate piece of legislation, the Fire Service Act, that covers (amongst other things) the procedures that govern the evacuation of buildings in the event of fire. This is the legislation under which the fire service operates and includes their powers to approve (or not) the evacuation scheme required by most commercial buildings.

A MAJOR SETBACK

In the mid 1990s, in areas totally unrelated to fire safety, it became apparent that there was a major problem with many of the domestic dwellings that had been recently built in relation to their weather tightness. Many were seriously defective and the 'leaky building' problem (which is still a problem) is costing many millions of dollars to fix.

The blame was laid at the door of inadequate building controls, and the liability was often ultimately left with the territorial authorities, as the original developers had disappeared. However, it also became apparent that the buildings had been constructed based on only very sketchy documentation with minimal justification of how the designs met the building code.

This has resulted in the territorial authorities becoming very risk-averse in all areas of building compliance. Any design that departed from the Acceptable Solutions was treated with a high degree of suspicion to the point where the time and effort spent justifying the design was often more onerous than the potential benefits that the alternative design could deliver.

In parallel with leaky buildings, there was some concern with the quality of fire safety designs that were being produced. Some designs were being approved based on very sketchy documentation and with limited justification. There were instances of buildings being denied their evacuation scheme approval, even though they complied with the building code (despite the legal position where features in excess of the Code could not be mandated). This has led to a lack of confidence in 'fire engineers' to produce designs that will satisfy the regulators and thereby meet the client's objectives.

In part, the blame for this situation can be laid with an inadequate process to develop a fire engineering brief in the early stages of the project. Some designs were undertaken almost in complete isolation of the remainder of the stakeholders outside of the direct project team. This was partially in ignorance of the importance of the process, but was also due to bad experiences with regulators who did not understand the concept of a performance-based design. A lack of general agreement on some of the basic design parameters also meant that some projects bogged-down as agreement could not be reached.

RECENT CHANGES

Move forward to 2004, and the Building Act was given a major rewrite with the intention of tightening the building controls and improving the level of documentation that was required before an approval to build (a 'building consent') could be granted. It also established a Design Review Unit (DRU) within the NZ Fire Service which is tasked with reviewing certain aspects of designs that are not wholly based on the Acceptable Solutions.

At about the same time, a task force was established under the umbrella of the IPENZ to investigate the state of fire engineering in NZ. The task force report² was published in late 2007 and included a series of recommendations for fire engineers and other stakeholders in the design and construction process.

The DRU is tasked with reviewing aspects of fire safety designs relating to means of escape and fire service operations that deviate from the Acceptable Solutions. They are intended to be independent of the design process and so will not engage in any discussions during the design process or during their reviews.

This has led to some friction with the practicing fire engineering community when review comments are perceived as being out of context of the design or asking for features that are seen as exceeding the requirements of the building code. Some territorial authorities have also been using the DRU for carrying out full peer reviews of designs - a task that is outside of their mandate.

It has also been recent experience that the amount of documentation and calculation (and hence cost to the client) required to justify an alternative design (even when based closely on the Acceptable Solutions) is disproportionate to the benefit gained by the design. Clients and their architects have less confidence that the performance-based design route will deliver any value or innovation.

CURRENT CHALLENGES

So to summarize the issues that the fire engineering profession are currently facing:

• Design documentation that is of a highly variable quality
• Regulatory authorities that are reluctant to accept alternative designs as these are seen as a liability risk
• Designs being carried out by unqualified 'fire engineers'
• A fire engineering briefing process that is underutilized and not well understood by designers or regulators
• A lack of consensus on basic design data
• A lack of consistent design implementation during construction

Another branch to the task force outcomes has been a drive to improve the quality of fire engineering design documentation. There have been some workshops held amongst the practicing fire engineering community to gain consensus on what is appropriate to include within the design documentation and how the design should be articulated. The move is away from a 'fire report' to properly separate the design specification (e.g., the requirements of the fire safety design that must be included in the designs of the architect and other design professionals on the project) and the design verification and calculations that demonstrate to the approving authority that the design meets the objectives of the building code. This is an ongoing program that will result in guidelines that will assist both fire engineers and those using their services.

SUCCESSES

However, it is not all doom and gloom. There have been some good examples of successful projects where the design team and other stakeholders have developed a fire engineering brief and followed through to a properly documented and approved design, with successful implementation in construction. These projects have recognized the value in investing time early in the project to gain agreement of the stakeholders.

An example is a recent major redevelopment of an art gallery where the client has been able to incorporate their own requirements and procedures for property protection to exceed the minimum Code requirements but also make use of this additional protection to allow a relaxation of other features that would otherwise have been mandatory.

There have also been some successful projects that have utilized specific fire engineering design as alternative solutions to the prescriptive documents, which have allowed the building design to incorporate features that would otherwise have been impossible. The client's input at the early stages of the design has encouraged their complete involvement in the process and enabled them to make well-informed decisions in the full knowledge of the possible outcomes.

The challenge remains to make these successes the benchmark for all projects.

THE FUTURE

Fire engineering has been in danger of being forced out of existence due to the perception that alternative designs were too risky (by the regulators) or did not deliver the benefits (to the clients).

However, with a move to more involve the stakeholders in the briefing process and to improve the quality of the design documentation, practicing fire engineers who are already doing quality designs, or those who recognize the problem and take action, will lift the discipline of fire engineering to where it should be.

The challenge is to maintain and increase the confidence of the clients and their architects to allow them to produce designs that are innovative without being stifled by the current prescriptive Acceptable Solutions.

Michael Dixon is with Stephenson & Turner NZ Limited.

References:

1. Building Industry Authority, Building Act, Wellington, New Zealand, 1991.
2. "Hot Topics - Fire Engineering Advisory Taskforce Report and Recommendations," IPENZ, Wellington, NZ, 2007.