UN built environment goals need a consistent carbon measurement system
With no globally consistent definition of a net zero building within the property sector, we consider the urgent steps needed to introduce standardisation on a global level.
It has become patently clear over recent years that built environment professionals have an enormous role to play in addressing the climate crisis. Yet our industry is not doing nearly enough. Buildings account for 37% of global energy related carbon emissions, and the 2023 Global Status Report for Buildings and Construction tells us that the sector is not on track to reach UN 2030 goals.
The report, launched at the recent UN-led Buildings and Climate Forum in Paris, shows building emissions are 15 percentage points behind where they need to be. If we are to stand a chance of meeting our goals and keeping global warming below 1.5°C, we must fundamentally shift how we measure and track carbon in the built environment, so that we can verify we are taking the necessary measures to halve carbon by the end of this decade.
Obviously, this paints a concerning picture. But there are many reasons to be hopeful. The solutions to decarbonise already exist. We know how to insulate buildings, replace fossil fuel heating systems with electric alternatives, improve building performance, drive down embodied carbon, and decarbonise the grid. Now, we must focus our efforts on implementing these solutions at scale and pace. But the first step on this path is establishing unified, effective carbon measurement systems.
Defining ‘net zero’ buildings
At its simplest, An operationally net zero building can be defined as one which is highly energy efficient, with low upfront and lifecycle embodied carbon, not connected to fossil fuel energy sources, supported by 100% on-site or additional off-site clean energy, and where unavoidable residual emissions are offset by long term carbon removal.
Each of these parameters is readily quantifiable despite the many complexities. However, the estimated proportion of new construction that is currently accounted for in this way is less than 1%. It is also estimated that each week humanity adds an area equivalent to a city the size of Paris to the built environment.
An internationally agreed definition for net zero buildings is crucial for robust national and local government policies, underpinning measurement, and transparent reporting, and providing clarity to the market that will generate real value from climate-adapted assets.
Unifying measurement
Consistent carbon measurement across the built environment is the basis for providing meaningful data on which to prioritise the planning, investment, procurement, and design decisions needed to drive down carbon. Without unified measurement and targets, we lack the information to chart a pathway and we lack adequate metrics to track and validate our progress.
A recent paper by WBCSD exploring the state of international WLC policy definitions revealed that, currently, there is no globally consistent definition of a net zero building within the property sector. Furthermore, despite the rise in corporate net zero commitments, there is no single national policy that requires buildings to be truly net zero now or in the future, or any set requirement to measure carbon emissions. Inconsistent and ineffective reporting is holding us back, preventing the growing demand for net zero buildings from driving a desperately needed market transformation.
The Declaration of Chaillot, signed by the 72 countries at the Forum, is a crucial step in the right direction. The Declaration commits to implementing roadmaps, regulatory frameworks, and developing mandatory building and energy codes. Currently, over 100 countries have no building energy regulations whatsoever, and less than 30% have performance regulations for the entire sector. The Declaration seeks to close this gap by promoting ambitious policies, unlocking finance, and supporting research and development. This intergovernmental commitment is a crucial foundation for the transformative change required in the built environment.
Affecting change at scale
At Arup, we have been developing a dataset of whole life carbon emissions, including material embodied emissions as well as the more widely understood operational emissions, across almost 1,000 projects in 30 nations and five continents. It is demonstrating how valuable comparable, consistent and granular carbon data can be to informing and prioritising carbon reduction decisions through the development cycle. Sharing such data and insights across our industry ensures that we can work together towards net zero goals.
To scale these efforts, we need widespread adoption of detailed whole life carbon assessments and transparent reporting. The building sector must collaborate to standardise the collection and sharing of carbon emissions data, develop harmonised tools and methodologies, and train engineers across the sector to use them effectively so that we begin designing in dual currency: carbon alongside cost.
Building for the future
At the same time, it must be acknowledged that a focus on decarbonisation alone will not be enough. Buildings must take into account other impacts of climate change we are facing. New buildings must be climate resilient, adaptable to increased risks of flooding, rainfall and extreme temperatures. No single element of this emergency can be addressed in isolation, just as no individual business or government can solve it alone.
Furthermore, we must take into consideration the varying societal impacts of the climate crisis globally. A transition to net-zero is carried out in a just and equitable way in all corners of the world, ensuring that policies and actions do not leave behind poorer communities, or the one-in-eight people living in informal settlements worldwide who are often the most vulnerable to the impacts of climate change.
While regulation is of course a vital component, policy changes often take several years to come into effect and whole systems-change will only occur with urgent action from everyone in the supply chain. Even greater collaboration across the supply chain is needed, using solutions which already exist. Assessing life cycle emissions is the first step to driving down emissions to meet our net zero goals.
Nigel Tonks is Director of WLC Transformation Lead, at Arup UKIMEA, a global collective of designers, engineers and consultants dedicated to sustainable development.
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Images: EJ Yao / Danist Soh