For New Zealand to achieve net-zero emissions by 2050, it must commit to urgent action in the design, building, and construction sectors.
The industry has both a challenge and an opportunity: to redefine how buildings are designed, constructed, and maintained to minimize their carbon footprint.
Decarbonizing the built environment is crucial for limiting New Zealand’s domestic emissions. This can be achieved through the lifecycle of buildings and structures, from their design, when choices can be made around the materials used, to their construction, operation, and maintenance.
One of the many ways to achieve Aotearoa New Zealand’s goal of reducing net emissions of greenhouse gases to zero by 2050 is for the building sector to develop and adopt low-carbon practices for designing, constructing, and operating buildings.
New Zealand’s building and construction sector was responsible for 7.4 Mt CO2-e emissions in 2018, representing 9.4% of domestic greenhouse gas (GHG) emissions. Additionally, outside emissions from the production of imported construction materials and products into the country is 2.9 Mt CO2-e of emissions. Although not included in New Zealand’s domestic emissions budgets, these emissions present a significant share of the sector’s total emissions (Aotearoa New Zealand, 2022).
The article by Rebecca Mill, the founder of The Lever Room, New Zealand’s leading carbon measurement provider, presents the current state of carbon accounting in New Zealand and how the design, building, and construction sectors can achieve their emissions reduction targets.
New Zealand’s design, building, and construction sector contributes 15% to the country’s total emissions. Under the Paris Agreement, the industry aims to cut its net emissions by half by 2030. Mills argues that one way to achieve this is to reject outdated carbon accounting methods and replace them with precise and localized carbon measurements.
She noted that the long-term impact of buildings is often overlooked in carbon accounting. With the county’s building floor area expected to increase by 75% in the next thirty years, the building’s long-term emissions pattern is crucial.
Architects and professionals in the sector will have a unique opportunity to lead the way in achieving these carbon emissions goals through innovative building designs that reduce operational and embodied carbon emissions.
Climate change shifts the focus of architecture from aesthetic-centered to wellness, sustainability, low-carbon, and environmentally friendly designs. In New Zealand, this shift also demonstrates respect for the Te Ao Māori (the Māori worldview), which places great significance on the natural world.
In 2020, after consulting with the building and construction sector, the NZ government developed a “Whole-of-Life Embodied Carbon Reduction Framework.”
The framework will require reporting and measuring the whole-of-life embodied carbon emissions from manufacturing materials to their disposal and cap the whole-of-life embodied carbon of new buildings.
According to NZ’s Ministry of Business and Innovation (MBIE), embodied carbon is the sum of all the carbon in the building’s materials and products and all the emissions associated with the manufacturing and production of materials, transportation, construction, and maintenance of the building throughout its entire life and even at the end of its life or when it is no longer used.
Over time, these emissions reduction requirements will become stricter, spurring new regulatory requirements and incentives for innovation and technologies.
The government’s push to lower buildings’ carbon emissions has led to initiatives to standardize the calculation, measurement, and reporting of embodied carbon. Companies like the New Zealand Green Building Council (NZGBC) developed a new carbon calculator in 2022.
The Building Research Association of New Zealand (BRANZ) released the LCAQuick, an Excel-based calculator, in 2023. Following the standardization of the embodied carbon measurements, oversight bodies are needed to ensure transparency and consistency. Audit and certification organizations such as the Toitū, Ekos, and The Lever Room have been established in New Zealand.
Low-carbon homes in New Zealand
A leading home builder company in New Zealand, Fletcher Building, launched an innovative, low-carbon, and sustainable home design. Homes are one of the significant carbon emitters not only in the country but around the world.
To reduce carbon emissions in home construction, Fletcher Building has developed various low-carbon home designs that will emit seven times less carbon throughout their lives. These designs will also result in less energy and water consumption throughout the house’s lifespan.
The company estimates that the average lifespan of a home is 90 years. The design also considers the embodied carbon of construction materials.
According to the company, considerable planning has gone into identifying the combination of systems and products that will reduce the embodied carbon of the construction materials.
The company says that although these low-carbon and sustainable homes have high upfront costs, these will be offset during their lifecycle due to decreased water and electricity usage.
According to studies, the primary goal of designing low-energy or low-carbon buildings is to optimize various factors, including orientation, structure, window and glazing placement, and the selection and size of appropriate materials.
Low-carbon homes must match conventional ones in comfort, safety, and durability. The fundamental purpose of homes is to provide a comfortable and secure environment for their occupants.
Consequently, prioritizing carbon emission reduction at the expense of building performance could hinder the advancement of low-carbon buildings.
Sources:
Aotearoa New Zealand’s first emissions reduction plan. Chapter 12 Building and Construction. (2022, May 16). Ministry for the Environment. Retrieved from https://environment.govt.nz/publications/aotearoa-new-zealands-first-emissions-reduction-plan/building-and-construction/
Mills, R. (2024, May 1). Architecture Now. Retrieved from https://architecturenow.co.nz/articles/building-change-the-carbon-measurement-glow-up/
Fletcher Building pioneers low carbon living with launch of innovative LowCO home. (2024, April 23). Fletcher Building. Retrieved from https://fletcherbuilding.com/news/fletcher-building-pioneers-low-carbon-living-with-launch-of-innovative-lowco-home/
Low Carbon Building. Science Direct. Retrieved from https://www.sciencedirect.com/topics/engineering/low-carbon-building
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