The basic form of a dwelling has remained the same until this current decade. I suggest that now is the time for a fundamental re-think.

A residential building’s orientation and its surrounding topography aren’t, and cannot sensibly be, regulated by the NZ Building Code and yet these two factors have very significant effects on the internal thermal performance of each dwelling within the building, no matter if they are terraced or part of an apartment block. The same applies to standalone homes.

With the current rapidly evolving move of our new housing developments away from standalone homes to medium density attached dwellings, I consider that there is an urgent need for a new approach to the fenestration forms of these new building typologies. In the past houses had all four elevations exposed to the elements. Now there often are only two or three, and even just one exterior wall. The growing awareness of the summer over-heating problems of these new dwellings requires new approaches to design.

Each summer we complain that a significant proportion of our homes are over-heating; and each winter express concern at the poor thermal performance of our older housing stock. The simple and quick fix is to install plenty of mechanical cooling, heating and ventilation systems, and appliances — but at what cost to the wallet and environment?

During the design and construction phases of a project there are stages at which attention can be given to evaluating and addressing any potential overheating.

While the NZBC-H1/AS1 Energy Balance assessment of Energy Efficiency demonstrates compliance for the purposes of obtaining a Building Consent, a dynamic multi-volume hourly passive thermal simulation of a dwelling’s passive thermal performance in its specific location and orientation is a much more relevant and useful starting-point towards providing a comfortable interior environment for the occupants over time. 

I understand that one of the purposes of the recent review of clause H1 (Energy Efficiency) of the New Zealand Building Code was to address the growing problem of summer over-heating of medium-density housing developments. I am not sure that a significant change has been achieved.

During the summer holiday, while I was driving about the North Island, I was aware of the continuing popularity of Black as the colour for exterior walls and roofs of recently built dwellings and terrace housing.

Following instruction from the Minister for Building and Construction (the Hon. Chris Penk) asking MBIE to review the NZBC-H1 energy efficiency standard, a range of comments were received early this year (2025). I understand that recommendations for changes are nearing completion. In the meantime the current requirements are still in place, and then there will be a Transition Period to allow the current compliance methods to remain valid before the changes take full effect.

This year major industries have been having significant difficulties with electricity pricing under the current market-driven pricing arrangements. With the growing number of Data Centres being established, the country needs to have a serious and comprehensive discussion on where and how our finite electricity supply is developed and used.