Power Minute:

Performance-Based Building Standards

Power Minutes explain an energy concept in less than one minute (300 words). Note: This is a living document, check back for updates.

Building efficiency standards have typically specified minimum requirements for each part of the building (different insulations, mechanical system, ventilation, etc.). Such standards are known as "Prescriptive". The problem with the prescriptive requirements is that all building parts are inter-connected.

As counter-intuitive as it may sound, prescriptive requirements are unable to keep different buildings to the same standard. For example, heat Loss in the building follows the path of least resistance so if a house has a lot of windows, the windows are the primary component of heat loss. In that case, the code must be stricter on the windows and more forgiving on other components. The opposite is applicable too, without many windows in a house, the code may be more forgiving to that element.

The prescriptive codes end up being a "one size fits all" solution for all buildings. In our example, regardless of how many windows the building has, it must comply with a static code, if it's prescriptive. The outcomes is construction inefficiencies and inconsistent outcome.

As a result, Performance-Based construction is gaining traction around the world, both for the building codes and for the standards. One example of such standards is the BC Energy Step Code.