One tool to rule them all?

This Issue This is a part of the Building for climate change feature

By - , Build 188

With the growing urgency to measure carbon emissions from building and create warmer, drier, healthier homes, how can evaluation tools help? A Building Research Levy-funded project has been asking industry.

A BRANZ stakeholder engagement project investigated the possibility of developing a tool that evaluates related variables including embodied and operational carbon, thermal performance, energy efficiency, moisture risk and indoor environment quality for new building design and construction.

Industry stakeholders were canvassed to identify the issues they face when evaluating building performance. These included MBIE Building System Performance, architects, designers and building consent authorities. As MBIE plans to set a series of operational and embodied carbon emissions caps that will decrease over time, there was a particular focus on calculating carbon emissions.

Stakeholder views

Stakeholders told us that we need to start reducing operational and embodied carbon emissions in buildings immediately, even if our evaluation tools are not perfect. However, other aspects of building performance should not be compromised by a focus on carbon footprint compliance.

While several tools are available, there was a preference for a single tool, specifically related to the New Zealand building industry, providing a wide range of building performance outputs based on consistent metrics.

The tool should:

  • be useable through the preliminary and developed design, compliance and construction phases, be viable for multiple building typologies and integrate with existing industry tools
  • be based on a consistent, regularly updated carbon dataset relevant to New Zealand
  • be freely available, easy to use and have a robust introductory training scheme with ongoing support
  • be simple and quick to enter data, with the potential to incorporate more detail as the design and construction processes progress
  • generate benchmarks based on a user’s portfolio of completed buildings and a wider pool of other buildings. These can be used to set targets at the beginning of projects for warm, dry, healthy, low-carbon buildings. It will also allow MBIE to collect stock-level carbon footprinting data that can be used to set future thresholds as part of its Building for climate change programme.

While a single tool is aspirational, the important factor is consistency – consistent design analysis and outputs across a wide range of building performance criteria combined with consistent assessment in the compliance process.

Manufacturers would also need to make reliable, current product data available, including the carbon footprint.

While the focus is on new builds, there will be a future requirement for evaluating alterations to existing stock and repurposed non-residential buildings.

For more

The full report Evaluation of building performance for low carbon houses will be available at

Download the PDF

More articles about these topics

Articles are correct at the time of publication but may have since become outdated.