Alternate Soluion

Performance Based Building Solutions

You have more than likely heard the terms Performance-Based Building Solution, and Deem-to-Satisfy building solution. But what do they really mean? And in looking for the best Alternate Building Solution, what is the best option?

Well, before I can answer this clearly, you should first understand what is a Deem-to-Satisfy Building Solution.

A Deem-to-Satisfy Building Solution is a prescriptive clause in the BCA that tells you exactly what to do. For example, “the rise of a stair must not be less than 115 mm and not exceed 190 mm”. It is clear and easy to follow, just like reading a recipe for baking a cake. It is a “one-size-fits-all” solution.

However, sometimes a “one-size” solution does not make for the best fit. Often there is a better solution available that is more cost effective and still achieves the same goal as a Deem-to-Satisfy solution. If we have a look at the issues and the actual circumstance of what we are trying to achieve, we can find better ways to reach the same result. This room for flexibility and innovation is referred to as a Performance-Based solution. The BCA introduced its performance-based code in 1996.

So, what’s the difference between the two solutions? Well, if we use the example of the maximum height of the stair that we discussed above, and expand that to the whole stair, we would see that the performance provision for a stair would be something like this: 

To ensure that people can move safely to and within a building, it must have stairways with—

  • slip-resistant stairway treads or near the edge of the nosing,
  • suitable handrails where necessary to assist and provide stability to people using the stairway,
  • suitable landings to avoid undue fatigue,
  • landings where a door opens from or onto the stairway so that the door does not create an obstruction, and
  • suitable safe passage in relation to the nature, of volume and frequency of likely usage.

As you can see, this performance clause provides no sizes or other easily measurable specifications to check compliance.

A performance clause uses words and phrases like “suitable”, “doesn’t create,” and “relation to the nature of” something or another. These flexible clauses leave room for solutions to be developed that meet these descriptive, non-recipe-specific parameters.

You may ask, so which is the better solution, Deemed-to-satisfy or Performance? The answer is neither. They both can be utilised to achieve the optimal result. This is a real advantage as it allows room for creative innovation to be part of everyday design.

If you would like to review a step by step guide on how to prepare a Performance-based Solution CLICK HERE.


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I am a Director of Devcert and have been a Building Surveyor since 1989. I have a bachelor degree in building surveying and I am a qualified carpenter. I have been in the construction industry since 1981. I have a real passion for the building certification profession as I believe building certifiers are the general practitioners of the construction industry. Our role is not only to know building law and apply it, our role includes assisting in the development of the knowledge of all in the industry by sharing our knowledge and experience.