University of Sheffield: Regulate whole life carbon in buildings to reach net zero, researchers say

Emissions from the full life cycle of buildings need to be regulated if the UK is to meet net zero, according to researchers from the University of Sheffield.

Dr Danielle Densley Tingley, an expert in low carbon engineering at the University, has called for whole life carbon – the emissions generated from the construction, maintenance and demolition of a building as well as from the energy used in its day-to-day operation – to be regulated for the first time in the UK to help tackle the climate crisis.

The call from the Sheffield academic has been made as part of a submission of evidence to an Environmental Audit Committee inquiry into the sustainability of the built environment.

From residential to commercial buildings, the UK’s built environment is responsible for 25 per cent of the UK’s greenhouse gas emissions.

Following the year-long inquiry, the Environmental Audit Committee (EAC) has now published a report, featuring contributions from Dr Densley Tingley and other experts from the University’s Department of Civil and Structural Engineering, warning that to date there has been a lack of government impetus or policy levers to assess and reduce these emissions. With climate deadlines looming, the report highlights how urgent action is needed.

To reduce the levels of CO2 in construction, Dr Densley Tingley and the EAC are calling for the government to introduce a mandatory requirement for whole-life carbon assessments for buildings. This requirement should be fully incorporated in building regulations and the planning system.

The UK is currently lagging behind countries such as the Netherlands and France which have established mandatory whole-life carbon assessments for their built environment, according to Dr Densley Tingley and the report.

Dr Densley Tingley, a Senior Lecturer in Architectural Engineering at the University of Sheffield, said: “Embodied emissions are contributing an increasing proportion of built environment emissions. These must be regulated to deliver the reductions needed to limit global warming and achieve net zero in the UK.”

The report from EAC is also calling for more buildings to be retrofitted and reused rather than demolished, keeping the carbon locked in, and for this to be prioritised over new builds.

While the government states it is prioritising retrofit and reuse, the EAC is concerned that reforms to permitted development rights appear to have created an incentive for demolition and new-build over retrofit. The government must therefore urgently evaluate the impact of recent reforms to ensure that retrofit and reuse are prioritised, according to the report.

Previous studies from researchers in the University’s Department of Civil and Structural Engineering have also called for more buildings to be reused rather than demolished and have highlighted the benefits retrofitting can bring, not only to the environment, but to towns and cities across the UK.

A recent study from Sheffield researchers has revealed how extending buildings upwards by up to two additional storeys could help to tackle the UK’s housing crisis and meet net zero commitments. The research found that two storey extensions could provide an extra 175,000 homes in one city alone whilst also boosting struggling high streets.

Following the high-profile closure of John Lewis in Sheffield city centre, academics from the University have calculated that even rebuilding the superstructure, rather than retrofitting the building, would emit over 4,300 tonnes of carbon – which is equivalent to the carbon emitted by 4,000 flights to New York from London, driving a car 17,000 times from Land’s End to John O’Groats, or running one oven for 800 years.

Researchers from Sheffield’s Department of Civil and Structural Engineering have also recently developed a new tool to help those involved in the design and construction of buildings to reuse more materials and engage with the circular economy in order to build more sustainably.

The regenerate tool encourages building life extension to reduce material consumption and carbon emissions.

Dr Densley Tingley added: “The culture of building demolition and replacement must stop, our existing buildings are a vital resource, produced with a considerable carbon investment. Priority should be placed on retrofitting and repurposing this existing stock to meet the UK’s built environment needs, and legislation must support and encourage this.

“Building reuse, rather than demolition and new build, saves the embodied emissions of the new build. Carbon should be invested in retrofitting this stock for improved energy efficiency, delivering typically a lower whole life carbon solution than demolition and rebuild.”