Demystifying net zero buildings

The impacts of climate change are becoming ever more evident: devastating wildfires, heavy flooding and heat waves are increasing in their frequency and their intensity. It’s hardly surprising that public concern around the issue is at an all-time high – in September, a poll found that climate change will affect how 54% of adults choose to vote, with this number rising to 74% for those under the age of 25.

Many governments, states, cities and corporations have responded to this convergence of science and public opinion, setting themselves net zero carbon targets (some as soon as 2030, but all by 2050). When we look at corporations, the real estate sector in particular has recognised its role in this transition.

“While net zero carbon may seem daunting, many in the sector are already committed to taking action.”

- Sachi Findlater, Net Zero Caron Expert, Upstream Sustainability Services, JLL

What does net zero carbon mean for real estate?

Globally, the construction and operation of buildings accounts for almost 40% of greenhouse gas (GHG) emissions – we cannot reach net zero carbon without significant and real efforts from the real estate sector. And those efforts need to start now – almost a third of building related GHG emissions (or 11% of global emissions) come from embodied carbon i.e. the emissions which are released in the manufacture and transportation of the materials which we use to construct our buildings in the first place.

In only the last year, more than 50 real estate occupiers and organisations, including The Berkeley Group and Salesforce, and cities including New York, have committed to achieving net zero carbon by 2050 or sooner. But what does net zero carbon really mean for the built environment and what myths need to be dispelled?

The lack of consensus on the issue has long been a point of confusion and in 2016 the World Green Building Council (WGBC) responded to the need for a consistent way of talking about net zero carbon buildings by setting up the Advancing Net Zero campaign. The WGBC developed a high-level definition of net zero carbon buildings along with a pathway to decarbonisation.

Aligning with the global ambition, earlier this year the UK Green Building Council (UKGBC) published its first framework definition for net zero carbon buildings and a target for achieving net zero carbon for all new buildings by 2030 (and all existing buildings by 2050).

The UK framework sets out a pathway to achieving net zero carbon buildings not only in operation, but in construction as well, recognising that the indirect embodied carbon emissions associated with the manufacture of construction materials can be responsible for as much as 50% of a building’s emissions across its entire lifetime.

While these changes may seem daunting, many are already committed to taking action. Some of the biggest cities in the UK have set their own ambitious decarbonisation targets. Manchester City Council has pledged to become a net zero carbon city by 2038, Bristol aims for full decarbonisation by 2030, while London’s Mayor has committed to achieve net zero carbon across London by 2050.

In the real estate sector, some are going even further than this; Hammerson has committed to becoming net positive in not only carbon, but waste and water as well by 2030.

Grosvenor recently announced their ambition to achieve net zero carbon in operation for their estate, including listed buildings, by 2030. They are also committed to reducing their embodied carbon emissions, taking an important step towards net zero carbon in construction.

The headline commitments from the Government, cities and the sector leaders have given strong signals on the willingness of the industry to implement change. Ultimately however, hitting the net zero carbon target will require fundamental changes across the industry, particularly in terms of energy.

At a basic level, it will mean switching to renewable power sources and moving away from the use of fossil fuels in buildings, like natural gas for heating. Low or zero carbon heating solutions are already being adopted in the market, as seen in Lendlease’s 25-acre Elephant Park development, powered by a Combined Heat and Power plant providing low carbon heat.

The challenge will be retrofitting older buildings, as this may require updating traditional energy systems, as well as changing internal layouts and facades. But, with only a maximum of two refurbishment cycles between now and 2050 there is limited opportunity to implement these changes; early action is needed to carefully evaluate the most cost-effective route to transition existing assets to zero carbon.

Given that much of the future performance of a building is dictated by early decisions, achieving net zero carbon,

both in operation and in construction, will mean changing the way that we approach design and construction and introduce circularity into the process. Designs which use fewer materials or materials with lower embodied carbon and using recycled steel and concrete where possible can have a huge impact on the embodied carbon of a building.

Finally, and most importantly, the industry will need to move to a performance focussed approach (as opposed to remaining compliance focussed – whether it’s Part L or EPC).

Net zero carbon is not a label, but a process which demonstrates that a building’s performance is being maintained at net zero carbon. This will require a shift in the whole value chain taking greater ownership of a building’s performance. There is already international best practice which we can learn from – The National Australian Built Environment Rating System (NABERS) scheme in Australia has demonstrated the huge positive environmental impact which can be achieved when developers change their approach to design to ensure that buildings meet the expected performance.

Recognising the clear benefits of this approach, a collaboration of over 20 real estate investors and delivery partners, led by the Better Buildings Partnership, have partnered with NABERS to implement the Design for Performance approach in the UK.

The real estate sector has a significant opportunity to support the transition to a net zero carbon economy in the UK. Despite the challenges, some of which are now demystified, we know it’s possible. With the first milestone set for 2030, a mere eleven years away, now is the time to implement these changes and begin to see tangible, positive impacts on our environment.

This article was published as part of “Transforming real estate: our views”, a digital magazine where our sustainability experts shed a light on how to navigate the current transformational path, giving you the tools and knowledge to ensure your business is future ready.