Simplicity & Performance
Simplicity There’s no free lunch. Incorporating more complexity into the new Code, like multiple climate zones, each with its own R-value set, allows construction to be more finely targeted to local circumstances. Such targeting reduces the risk of “gold plating”. On the flip side, these more complex arrangements increase the burden of compliance checking, add more variables for builders to negotiate, and complicate the starting point for future changes to the Building Code. Our preference, as hinted already, is for less complexity. We recommend maintaining 3 climate zones and restricting Code changes to a few high impact variables, with a core
focus on high-performing windows. We have demonstrated that one ambitious, yet affordable, design can deliver significant energy savings in all climate zones. While it is true the NPV of savings from are lower in the warmest climate zone, the NPV is nevertheless positive. Not all energy saving improvements to the building envelope are equal; the contribution of high-performance windows is hard to ignore. In our submission to MBIE we urged that changes to the Code be kept to a small number, focused on the components that deliver the greatest electricity savings, at the lowest cost. This was to support simpler implementation of high impact changes.
