Building Change: Carbon emissions and certifications

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With only six years left to meet the ambitious carbon reduction commitments of the New Zealand Government, the architecture and building sector is feeling the heat.

With only six years left to meet the ambitious carbon reduction commitments of the New Zealand Government, the architecture and building sector is feeling the heat. Image: Xiaohu Yan, Sandra Baggerman, Cas Esbach

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Rebecca Mills, Managing Director, The Lever Room.

Rebecca Mills, Managing Director, The Lever Room. Image: Supplied

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Rebecca Mills, director at The Lever Room, Aotearoa’s longest-standing sustainability and carbon measurement provider, explains why carbon measurement methods are and aren't adding up in 2024. Here, she evaluates the present state of carbon measurement in this country and what specific blind spots and challenges are presented when calculating carbon emissions for the built environment.

As we stand on the cusp of a pivotal decade where global emissions must be halved, the design, building, and construction sector in New Zealand emerges as a crucial player in this endeavour. While this sector currently contributes around 15% of the nation’s greenhouse gases, its significance on a global scale cannot be overstated, accounting for over one-third of global energy consumption and emissions.

In committing to the The Paris Agreement in 2016, the New Zealand Government has set ambitious targets to reduce carbon emissions, aiming for a 50% reduction in net emissions by 2030. Sustainable design coupled with precise, localised carbon measurement data is instrumental in achieving these goals.

Rebecca Mills, Managing Director, The Lever Room. Image:  Supplied

It’s imperative that we critically assess carbon emissions and adopt sustainable design practices to future-proof our cities and homes. By rejecting outdated approaches to carbon accounting and embracing innovative strategies, we can pave the way for a more resilient and low-emission future.

One often overlooked aspect is the long-term impact of our buildings, which sets emissions patterns for the future and influences emissions across various sectors. With projections indicating a 75% increase in floor area over the next 30 years, the need for decarbonisation efforts in the sector becomes even more pressing.

Acknowledging that the construction sector is a significant contributor to greenhouse gas emissions and waste, it’s clear that rapid transition toward net-zero carbon practices is essential to mitigate climate change and preserve nature.

The multi award-winning Scion Innovation Hub by RTA Studio and Irving Smith Architects. Image:  Patrick Reynolds

Are architects New Zealand’s next sustainability champions?

Architects and professionals in the building and construction sector have a unique opportunity to lead the way in innovating and adapting to low-emission methods. By focusing on reducing both operational and embodied carbon emissions, we can make substantial strides toward a more sustainable built environment.

The introduction of stricter carbon measurement standards, including mandatory reporting requirements and caps on embodied carbon, signals a positive shift toward more comprehensive emission reduction strategies.

Stricter carbon measurement is coming

In 2020, the Ministry of Business Innovation and Employment (MBIE) consulted with the building and construction sector on proposals to introduce mandatory reporting requirements and eventually caps for the whole-of-life embodied carbon of buildings. Sector feedback indicated support for these proposals.

The Government consulted on a ‘Whole-of-Life Embodied Carbon Reduction Framework’ in 2020. The framework would require reporting and measurement of whole-of-life embodied carbon emissions – from manufacturing building materials to disposing of them at the end of a building’s life. The framework would cap new buildings’ whole-of-life embodied carbon and reduce the cap over time.

Over time, the levels of emission reduction required will increase. We’ll focus on a broader range of measures including new regulatory requirements, behaviour change programs, incentives and support for new technologies and innovation.

Taking a circular approach, a whole-of-life building assessment takes into account the footprint, construction, operational emissions, structural sustainability, and maintenance of a building over its lifetime. Image:  Xiaohu Yan, Sandra Baggerman, Cas Esbach

Defining a building’s whole-of-life embodied carbon

The embodied carbon of a building is the sum of all the greenhouse gas emissions that occur at each stage of its life cycle. Emissions are measured in units of kg CO2-e. In LCA studies, they are reported in the environmental impact category known as ‘Global Warming Potential’ (GWP).

A building’s whole-of-life embodied carbon according to the technical method released by MBIE in 2022:

  • is the sum of the embodied carbon of the constituent materials and products in the building, to the extent that it includes those elements that make the most significant contribution to the total embodied carbon of the building,
  • includes all the emissions associated with these materials and products that occur right across their lifecycle, namely production and manufacture, transportation and construction processes, maintenance activities, and what happens when the building is no longer used (end-of-life),
  • excludes emissions associated with the operation of the building, typically from energy used for heating, cooling, lighting, and water consumption.

The mandatory scope of an embodied carbon assessment shall initially include the significant elements of a new building that perform the primary functions of the building.

Impact measurement becomes the standard

Clear organisational and project-specific sustainability strategies, coupled with robust carbon measurement and impact assessments, will become standard practice for architecture and engineering firms. Collaborating with organisations specialising in carbon measurement and lifecycle analysis will be key to navigating this evolving landscape effectively.

All architecture and engineering firms will need to have in place clear organisational and project-specific sustainability strategies, carbon measurement and impact assessments and there are several organisations in New Zealand that can help develop these.

What’s considered “green” and what’s not will largely depend on the accuracy of the tools used to measure a building’s past, present, and future impact. Image:  Xiaohu Yan, Sandra Baggerman, Cas Esbach

The New Zealand market currently consists of audit and certification organisations such as Toitū, Ekos and The Lever Room. Furthermore, there are a number of science-based practitioners, including Thinkstep and The Lever Room, that have the additional capability to advise on how to best streamline and undertake the heavy lifting on carbon measurement and lifecycle analysis.

As we transition toward mandatory reporting and caps for embodied carbon, it’s increasingly important to recognise the limitations of generic LCA tools and embrace more nuanced approaches tailored to local contexts. While challenges may arise, working alongside sustainability experts with extensive experience and global connections will ensure resources are well spent and that efforts are focused on the most impactful initiatives.

In conclusion, while the road ahead may present challenges, it also provides opportunities for innovation and positive change. By embracing sustainable design practices, leveraging precise carbon measurement techniques, and fostering collaboration across sectors, we can forge a path toward a more sustainable and resilient future for generations to come.


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