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Do perfomance-based standards reduce quality?

What's the link between a multi-million dollar fire in an industrial area and a flock of parrots chewing up the facade of a block of luxury units?

The answer is performance-based building standards.

Now, don't get me wrong: I love performance-based Standards. Really! They give all players in the supply chain the potential for massively increased flexibility to deliver cost effective and innovative solutions when compared to the old "thou shalt" prescriptive regulations, to everyone's gain. And that's the mantra of all supporters of performance-based Standards, isn't it?

But something not so commonly stated and in my experience not so well understood through the industry is that using such a flexible and wide-ranging tool requires a clear understanding of the limits of design and limitations of performance of existing materials and practices and more, imposes a greater responsibility for everyone associated with a project to work together to ensure the finished product does meet the quality criteria specified.

The old Standards were to a large degree empirical, the requirements built up over decades of trial and error. In addition, relatively large factors of safety were incorporated to, as one of my old degree lecturers used to put it, maintain the balance of equilibrium between the inherent limitations of design, construction and materials. He further said that we tinkered with this equilibrium at our peril. Wise words, and unfortunately ones which often go unheeded in the application of performance criteria.

Adjusting the balance requires understanding of all aspects of the dynamic process of building and how changing one factor might impact on the others. Sensitivity effects, often known as the "butterfly effect" (named after the analogy that a butterfly's beating wings in the Amazon might create the conditions for a storm somewhere else in the world) ensue, with small changes in one part of the system possibly having greatly magnified (and costly) effects elsewhere later on. What do I mean by this?

One example is where dealing with Alliancing or Design & Build contracts, the specification and design are refined (and sometimes effectively reduced as costs are reassessed), often several times between creation and actual construction.

This, coupled with other changes such as:

means the risk profile is undoubtedly increased - and increased risk should be factored into project costing, not accepted automatically without consideration.

One of my concerns particularly is the mixed mindset held in some quarters. One the one hand, this mindset says any designs and specs can be pared down as the assumption remains that "there's plenty of fat " in there to begin with. On the other hand the minset grabs at the savings offered by performance-based design which , by definition, tend to reduce the factors of safety that were inherent in the old Standards! Clearly this can be a real problem.

On occasion, there is a laissez-faire attitude to this risk. If it goes "a bit wrong" it seems can be less a case of that butterfly in the Amazon, more a case of "if a tree falls in the forest and I'm not there to hear it, it won't make a noise".

How does this link to parrots chewing at the facades of luxury appartments or fire damaged industrial buildings?

Non-structural elements, such as applied facade features should be specified understanding the environment and their intended life. Similar damage from animals (birds, rats) and possible weathering (at an increased rate to the main concrete exterior) has been well documented. But, though relatively cheap these products can be absolutely appropriate in certain applications.

Fires occur. Again performance statements allow the final building solution to follow many forms. Increasingly, this means no sprinkler systems (they're expensive!). In our case, the fire brigade spokesperson stated two well established principles of modern fire fighting. Firstly, the fire would most likely not have taken hold if there had been an operating water sprinkler system. Secondly, in order to preserve life, the fire brigade will most likely remain outside

a non-sprinklered premises to contain the fire with the empahsis on life saftey and not attempt to save the building and contents -i.e. the business. Consequently, this must influence the likelihood that the businesses affected will suffer significantly greater disruption. And there are many businesses that never recover from fires - upto 60% by insurance industry estimates!

Performance statements can state almost at will that they are. But we need to ask some important questions early on in the project process, like:

In scoping, designing and building our projects, are we listening for the quiet beat of those butterfly wings?

If you would like to explore ways to avoid the "butterfly effect" on your next project, call Philip Sanders on 0401.01.202 or email him at psanders@bknexus.com for a brief, obligation-free consultation.

Contact us at info@bknexus.com or give us a call +61 401 010 202

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