Embodied carbon: Should ‘net-zero’ buildings require carbon-neutral construction?

EXCLUSIVE: Amid calls for ministers to implement policies that ensure all new buildings are built to carbon-neutral standards by 2030, key construction industry stakeholders are beginning to ask whether the definition of "net-zero" should cover embodied carbon as well as operational emissions.

The question was one of the key discussion points for a panel of sustainability experts from Landsec, EDF Energy, Intercontinental Hotels Group (IHG) and the UK Green Building Council (UKGBC), who last week discussed how the built environment sector could spur the transition to a low-carbon economy and help the world achieve the goals of the Paris Agreement.

The discussion formed part of edie’s green buildings webinar, which took place last Thursday (27 September) and is now available on demand. The hour-long webinar, hosted in association with EDF Energy, saw panellists provide practical advice and expert guidance on how energy and sustainability professionals can embed new technologies and initiatives to decarbonise building stocks.


The webinar saw speakers debate whether an industry-led definition of “net-zero”, which UKGBC is in the process of co-creating with its 400 members, should apply to emissions at every stage of a building’s lifecycle, instead of solely to direct operational emissions.

UKGBC’s senior policy advisor Richard Twinn explained that most professionals currently take net-zero to account exclusively for operational emissions due to a shortfall in the level of technology, infrastructure and understanding that would be needed to include embodied carbon.

“[The narrower definition] makes sense from a building point of view and is something that is really achievable now, in terms of the technologies we’ve got and the understanding that we have of how buildings operate,” Twinn said, noting that only a small proportion of the world’s building stock is currently operating at a carbon-neutral level.

“Whole-life emissions is a much more fundamental question that we are going to need to get into in the years down the line. At the moment, I think the problem with net-zero whole-life carbon is that you would be paying an offset for all upstream emissions from manufacturing and transport, without controlling them. However, this is ultimately where we need to get to.”

Twinn concluded that a truly holistic definition of net-zero would require significant decarbonisation in the transport and heavy industries sectors, which would prove to be more of an “economy-wide” challenge.

Echoing Twinn’s sentiments, Landsec’s Byrne added that the question of whole lifecycle carbon was one which “could not be glossed over”.

He explained that the company, which is working towards a science-based target of reducing its emissions intensity by 80% by 2050, treats its portfolio of properties as a single entity and undertakes lifecycle analysis for its entire estate.

Indeed, Landsec’s Scope 3 emissions – which are accounted for by “indirect” sources such as transport, manufacturing and service use – are made up a staggering 91% of its carbon footprint in 2017.

“Net-zero carbon buildings in operations is a fantastic target – but we also need to look at emissions associated with Scope 3 and those associated with how we build our buildings as well,” Byrne concluded.

EDF Energy’s Vincent de Rul agreed with the other panellists, explaining that most professionals he works with are building the business case for decarbonisation on cost savings from operational efficiencies, rather than the benefits of a net-zero lifecycle.

“The importance of making an energy efficiency journey and taking a net-zero approach will require you to save, manage and secure your energy and, to do this, you need to make sure that you can design, build and maintain the assets that you are implementing,” de Rul said.

“The capability to secure long-term energy efficiency is not only in the design solution but also in the capacity to build correctly and to maintain a set level of performance.”

Policy and pacing

During a Q&A session after the panel discussion, the speakers were asked what policymakers could do to make net-zero the new normal in the UK’s built environment sector.

The policy background has arguably been favourable to those wishing to take sustainability action in recent times, with the Government this year setting a course for halving building energy use and emissions through its £420m construction sector deal. The deal came shortly after the Government struck an agreement with the construction industry to halve emissions in the built environment over the next eight years.

Nonetheless, ministers and the homebuilding industry alike continue to face scrutiny for “spurning” low-cost carbon reduction options such as home insulation. The Committee on Climate Change (CCC), for example, recently claimed that the cancellation of Government incentives for insulation has caused a 95% drop in installations since 2012.

UKGBC’s Twinn echoed the CCC’s concerns, explaining that low-cost loans and tax incentives would encourage retrofits of low-carbon technologies by bringing down upfront costs. He also highlighted UKGBC’s calls for the Government to announce a trajectory for improving building regulations, arguing that a large proportion of the development market would only make progress in line with regulatory updates.

IHG’s director of corporate responsibility for environment & commercial integration, Lindsay Wilkinson, agreed and said that Government incentives were a “huge driver” of sustainability success in the US.

She cited the UK’s CRC Energy Efficiency scheme as a policy that requires businesses to divert funding away from low-carbon investments such as heating, cooling and cooking facility upgrades and into compliance.

De Rul suggested that the Government should move to make 100% of its building stock net-zero in order to “lead by example”. He explained that doing so would show industry stakeholders and the general public that adopting the standard was “feasible” and that doing so is important.

Sarah George

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