Factory-made homes cut carbon emissions by 45%

Substantial embodied carbon emissions savings were unearthed by academics from Cambridge University and Edinburgh Napier University in a study on a high-rise and a mid-rise modular scheme in London.

The buildings totalling 879 homes were delivered by Tide Construction using its modular system. University academics found that 28,000 tonnes of embodied carbon emissions were saved from construction – the equivalent of the CO₂ absorbed by 1.3m trees in a year.

(l-r)44 and 38 storey George Street in Croydon, now known as Ten Degrees and The Valentine in Gants Hill, London Borough of Redbridge were measured

This is well ahead of industry targets and shows a switch to modular construction could radically reduce the carbon footprint associated with the UK government’s ambition to build 300,000, better quality homes.

Embodied carbon, the CO₂ produced during the design, construction and decommissioning phases of a development, is slashed because buildings require lower volumes of carbon-intensive products such as concrete and steel.

The report, “Life Cycle Assessments of The Valentine, Gants Hill, UK and George Street, Croydon, UK” also shows emissions were lower because indirect carbon emissions from deliveries and on-site workers are reduced.

Dr Tim Forman, senior research associate at University of Cambridge, said: “Buildings are responsible for approximately 40% of global energy-related carbon emissions, and there is an urgent need to reduce the carbon intensity of construction and buildings in use.

“As buildings become more energy efficient in operation, reducing the carbon associated with construction — including the production and transportation of materials and site activities – and their end of life is becoming increasingly significant.

“This study underscores the fundamental importance of quantifying carbon in construction and across a building’s life cycle.”

Professor Francesco Pomponi of Napier University, said: “This study is a truly comprehensive and robust life cycle assessment of the modular solution.

“The analysis of two residential buildings was conducted in accordance with the latest carbon assessment guidelines, and analysis was based on conservative assumptions and a careful selection of data inputs.

“While further studies should be completed to deepen our understanding, the research makes a compelling case for the embodied carbon-saving benefits of modular construction.”

Test buildings in the research project

The study found that:

Two schemes achieved embodied carbon savings of 41% and 45% respectively over traditional construction.
The embodied carbon values of each building are significantly lower than current industry targets set by RIBA and LETI.

Each scheme was selected because of being recently completed and representative of its distinct type, demonstrating the versatility of Tide Construction’s Vision Modular system across both high-rise and mid-rise buildings.

George Street in Croydon, which is the world’s tallest modular tower, comprises two terracotta-clad buildings of 44 and 38 storeys respectively with 546 homes, and The Valentine in Gants Hill, London Borough of Redbridge, a brick-clad 333-bed student accommodation scheme over 10 storeys.

Both schemes were completed in 2020, with architecture by HTA Design.

Christy Hayes, CEO at Tide Construction, said: “The striking results of this study show that the Vision Modular system can significantly reduce the embodied carbon footprint of buildings.

“Modular brings investors, occupiers and their professional teams a great opportunity to significantly reduce whole-life carbon emissions, supporting their environmental, social and governance plans and access to green finance.

“Tide Construction & Vision Modular commissioned this study to prove the sustainability of our system and to support our continuous efforts to further reduce construction’s carbon footprint.”