The John Lewis building in Sheffield city centre now stands empty. The fate of the building, acknowledged for its energy inefficiency, has sparked debate as to whether to demolish and rebuild the structure or retrofit the building and conserve the carbon already locked in the walls.

Proposals for the John Lewis building focus on demolition, followed by either a full rebuild, the building of a smaller civic building and an extension to Barker’s pool, or the complete replacement with a large park. Retrofitting campaigners, including a group of architects calling for a full building retrofit rather than demolition, have instead proposed an alternative green retrofit, which would conserve carbon stored within the building and avoid demolition.

Benefits of Retrofitting

Carbon equivalents as retained within the building during a retrofit. Image from Urban Flows Observatory

Replacing the building with a green space may seem the most environmentally friendly option but this may not be the case. PhD student Danielle Abbey, a member of the Urban Flows Observatory, calculated that the existing walls of the empty building contain 4,700 tonnes of carbon, the equivalent of 4000 flights from New York to London. 

Retrofitting the building would retain this carbon which would otherwise be lost through demolition, making repurposing a greener option than demolishing and planting a park. Using the existing shell would also cut down on transportation costs, elevating this project’s green credentials, as well as retaining the nostalgic building within the heart of Sheffield.

Green retrofitting is gaining traction within the architectural world. According to the World Green Building Council, buildings are responsible for 39% of global energy-related emissions, including 11% from materials and construction. Retrofitting reduces these emissions as less concrete and infrastructure is required in doing up an existing building.

Principles of retrofitting

Retrofitting is the process of adding and fixing old systems with new technologies. In an architectural context, this means fixing a broken building by reinforcing the infrastructure instead of knocking down the building, only for another construction to take its place.

The building is suitable for retrofitting, due to high ceilings and ideal location within the city centre. Retrofitting would require extensive work to make the building suitable, including: stripping out the mechanical, electrical and plumbing systems; reviewing the fire escape provision; designing a new envelope and fitting the building out; removing and disposing of asbestos; and demolishing the existing car park.

Examples of Retrofitting

The John Lewis building would join the ranks of such including 1 Triton Square in London and the Empire State Building in New York, which have had a ‘green retrofit’ to increase energy efficiency and update the facades. Green retrofits will increase sustainability of homes, and this building could be a flagship for such work at the centre of Sheffield. It will also play a crucial role in updating the sustainability of our homes without rebuilding all existing structures.

Reticence to retrofit?

Retrofitting is better for the environment by using existing structures, but you may ask why is it not the automatic go-to? At the moment, it makes greater financial sense to demolish the building and rebuild, at a saving of around £40 million according to the Development Manager Queensberry

This does not consider the value of the stored carbon which will, however, be lost. The question is whether we start valuing carbon in the same way as we value monetary savings in the midst of an environmental crisis. Retrofitting such an iconic building at the centre of Sheffield could be the example we need to begin shifting to a more climate conscious perspective.