It’s time to get serious about the impact of building on the environment – in particular, on the overarching issue of climate change.
Buildings are well understood as among the largest emitters of carbon dioxide (CO₂) – from the construction phase of their life cycle onwards. Internationally, the built environment has been estimated to contribute 39 percent of all carbon emissions – 11 percent being from embodied emissions, or upfront carbon from materials, transport and construction processes and 28 percent from operations.
Don’t think this is a receding issue because demand for office space has been restructured down by Covid. It hasn’t – market data shows demand is strong and I think we can assume that the fundamentals, like economic growth and the need for meaningful human interaction in work, remain the long-term drivers.
There are many people and organisations doing worthy work to optimise or regulate the use of building materials, and to develop technologies, to minimise emissions over the long term. That’s all good, but there is a bigger problem – we might call it the elephant in the building – which is our bias in favour of constructing shiny new buildings, scrapping those already in place and sending much of the used material to landfill
That bias, with the waste that results from it, creates a body of carbon emissions that will never be mitigated by operational efficiencies or technologies.
It’s a better environmental proposition to preserve and upcycle existing buildings, avoiding the carbon debt that new ones incur in their creation.
As a rule of thumb, more than 60 percent of embodied carbon emissions in a building are associated with the sub-structure, frame, upper floors and roof. Well designed and executed upcycling works can retain these elements, providing substantial cuts in the embodied carbon footprint, and achieve an improved environmental outcome from the ongoing operation of the building.
The case is starkly illustrated by a study of our refurbishment at 1 Albert St, Auckland. We commissioned independent consultants to undertake a high-level embodied carbon assessment for the building. This found that building it new on a like-for-like basis would have had a global warming impact 2.5 times greater than refurbishing and upcycling. This calculation assumed a life cycle of 60 years and normal efficiencies in heating, ventilation and air conditioning for both the new build and refurbishment options.
We are committed to an investment strategy based on identifying and driving value within existing office buildings without incurring the carbon debt of new ones. There are three parts to our approach:
In line with that strategy and to contribute to a lower-carbon future for New Zealand, we aim to have our office properties achieve a 4-plus Stars NABERSNZ rating, or equivalent, over time. (The NABERS system, launched in Australia in 1999, is an internationally recognised energy rating tool for commercial buildings.
Obviously, there will always be a need for some new building – for example, to replace buildings that are seismically flawed or to provide urban infrastructure.
Given there is such ample potential for substantial and much-needed reductions in carbon emissions from new builds, you might ask why there is not yet a massive shift towards refurbishment. I suspect the answer lies somewhere between the beguiling prospect of technological gains and/or operating efficiencies and a desire to avoid heavy-handed regulation.
In fact, while new builds are generally marketed largely on the basis of these gains and efficiencies, the case doesn’t stand up to close examination. Those benefits can usually be achieved to a similar standard under an upcycling programme.
In regard to regulation… New Zealand has committed to net zero carbon emissions by 2050 and there is an aspirational policy framework to ensure that the building and construction industry plays its part in the necessary reductions. The collection and reporting of data, along with a sinking cap on emissions per square metre of built space, is the preferred approach. Hopefully, that will promote the environmental advantages of refurbishment over new builds.
I believe the greatest impetus will come from market pressures, whereby tenants and other occupiers demand commercial spaces that are consistent with their own environmental values and standards. They are becoming aware that long-term cuts in building emissions are not enough to reduce the risks associated with climate change – emissions also need to be cut now.
Mark Gedye is General Manager of Real Estate for Auckland Real Estate Trust.
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