NZGBC lays out emissions reductions through better buildings Emissions reductions of 30% are possible. And it’s not even hard.

19 May 2024 by Jason Quinn

NZ Green Building Council’s latest report is well worth reading. In my view, the policy changes it recommends are easy (we could do more). Buildings are capable of delivering about a third of the carbon emission reduction that New Zealand is required to do—the government signed agreements and those commitments are now part of our trade agreements. If we choose to not follow this practical approach, we’re choosing to pay way more later through buying carbon offsets overseas.

“Bold but practical policies”

The report makes the case for “a set of bold but practical policies to improve the energy efficiency of our buildings can reduce New Zealand’s emissions by 6,100kt* between 2026 and 2030, significantly closing the gap between New Zealand’s emissions goals and our current path. Emissions savings would continue to accumulate beyond 2030, delivering 93,000kt of savings by 2050, equivalent to taking half of the current petrol car fleet off the road permanently.”

The report identifies practical, low-cost steps that aim to reduce both embodied and operational carbon emissions:

  • an improved Building Code
  • phasing out fossil gas in homes and commercial buildings
  • making energy use transparent via energy labelling of commercial buildings and homes.

The authors point out that while carbon emission reductions are urgent, these policy changes would bring about other important benefits too, which benefit New Zealanders and save a lot of money:

“Transpower’s 2020 Te Whakamana I te Mauri Hiko3 report sets out that demand for electricity is to rise over 70%. Saving energy, as these policy proposals will do, significantly reduces the need for new generation and frees up energy for use for other sectors such as electric vehicles.

Peak load is an issue in New Zealand. We often have a significant demand for electricity in winter months that cannot be met in drier years. Analysis of our energy system4 shows that this peak in demand is almost completely down to residential space heating. It reflects the poor quality of New Zealand housing stock.

New Zealand homes are often chronically underheated, leading to significant health issues. Building to higher standards and retrofitting homes to energy-efficiency standards, as proposed in this paper, can help reduce peak load significantly and so help to reduce many of our health problems.”

The report’s data on carbon savings are based on in-depth research provided by BRANZ, NABERS, the Climate Change Commission and others.

The report is very well presented and referenced and I recommend a thorough read to understand the numbers and implications.

More reading

Tucked in amongst the report’s extensive references is a link to a BERL report for the NZGBC in 2022. Nick Robertson and Hugh Dixon authored “Near zero emission houses and offices”. It’s worth close study and is available free online.

I also recommend this paper by Otago University’s Michael Jack and others, “The role of highly energy-efficient dwellings in enabling 100% renewable electricity,” in the journal Energy Policy.

Official citation
M.W. Jack, A. Mirfin, B. Anderson, “The role of highly energy-efficient dwellings in enabling 100% renewable electricity,” Energy Policy, Volume 158, 2021, 112565, ISSN 0301-4215

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