Cambridge Institute for Sustainable Leadership said its new HQ will set ‘world first’ for sustainable refurbishment of an older office building

Work has begun in central Cambridge to transform a telephone exchange building built in the 1930s into an ultra-low carbon office building that will set a number of new standards for sustainable energy, emissions, and resource use, according to its backers.

The low carbon building is set to become the new headquarters of the Cambridge Institute for Sustainability Leadership (CISL), providing office space for local staff, a “virtual hub” for international partners and colleagues, and a base where CISL’s numerous digital learning programmes can be crafted and delivered.

Unveiling the plans for the green retrofit this week, CISL said the low carbon building – to be named Entopia – is set to become an international exemplar for sustainable office retrofits and would demonstrate how an existing office building can be made highly energy efficient through its redevelopment and use.

Overall, the retrofit is projected to result in an 80 per cent saving in whole life carbon emissions compared to a standard office refurbishment and deliver 75 per cent lower heating demand in comparison to an average office building, CISL said. Meanwhile, significant investment in the fabric of the building will allow it to shoot from an Energy Performance Certificate (EPC) rating of E to an A rating, it added.

Dame Polly Courtice, founder and director of the institute, said the pioneering building would contribute to CISL’s continued development and provide leadership for a sustainable economy.

“CISL’s new HQ at The Entopia Building will exemplify and enable our mission to support and inspire the leadership and innovation we need to transition to sustainable economy,” she said. “Our aim is to create a highly collaborative and sustainable workspace to bring together Cambridge’s academic and innovation communities with our network of companies and sustainability leaders to accelerate solutions to global sustainability challenges.”

The low carbon sustainability hub is aiming to achieve multiple sustainable building certifications, including BREEAM (Outstanding), the Passivhaus ‘Enerphit’ standard for building refurbishment, Well (Gold) certification, and will be aligned with circular economy principles to minimise its use of natural and man-made resources, according to CISL.

The £12.8m retrofit has been supported by a £6m donation from digital energy company Envision Group and a £3m grant from the European Regional Development fund. The University of Cambridge has also invested its own funds in the project and provided a internal grant from its energy and carbon reduction project.

Alexander Reeve, sustainable building advisor at the University of Cambridge’s estates division, said the refurbishment was an important “pathfinder project” for the university as it worked to phase out fossil gas as a fuel from older buildings.

“Through the project we have been able to demonstrate the viability of measures such as internal wall insulation and triple glazing which have significantly reduced the size of the air source heat pump installation and avoided the need to upgrade electrical substation capacity,” he said. “This means the only significant external alterations are the glazing and a solar power photovoltaic array on the roof.”

More than 350 LED lights installed in the Entopia building have been recycled from another building refurbishment. Meanwhile 21,600 kilograms of chairs, tables, and storage installed in the building prior to the refurb have been donated to local communities, generating significant carbon savings.

Stephen Toope, vice-chancellor of the University of Cambridge, emphasised the building would help the university meet its aim of reducing its energy-related carbon emissions to absolute zero by 2048.

“The Entopia Building will become the most sustainable premises in the University of Cambridge estate, marking a major contribution to our world-leading target to eliminate our emissions and putting the wellbeing of its occupants – and wider society – at its heart,” he said.