Researchers in Bath have used the abundance of stately homes in the region to bring some science to the art of retrofitting old and protected buildings with alternative energy sources.

Many historic buildings are, of course, highly energy inefficient and updating them can be a huge challenge. Retrofitting such iconic buildings with energy saving technologies is controversial as some of the building’s historic elements may be altered or covered up.

The team at the University of Bath devised a new approach to balance the need to reduce the carbon emissions of these buildings whilst retaining their heritage character.

Using a three-step process, they interviewed 116 members of the public and asked them to rank the acceptability of 15 potential energy saving retrofit measures which could be applied to historic buildings. Uniquely, this was done by showing the public photographs of the technologies on other old buildings, thereby helping them to understand the visual implications. Such measures included installing solar panels on the roof, draught-proofing windows and doors, and applying insulation panels to the building’s exterior façade.

The researchers then tested the energy-saving retrofits on buildings using an energy model to provide a separate ranking of the retrofit measures based on their energy-saving ability. Both the public’s acceptability ranking and the energy-saving rankings of the retrofit measures were then compared. The results showed that those interventions that saved the most energy (namely, draft proofing the ground floor, installing log burners in fireplaces, draught proofing of windows and doors, placing old windows with double-glazed replicas, and installing modern radiators and gas boilers), were not those thought to be the most visually unacceptable.

This could help conservation officers and architects by clearly highlighting those measures which were both effective in saving energy and deemed as preserving the visual character of the building, assuring them that they are not discussing options that are both unappealing to the public and save little energy.

“Understandably, conservation has been led by conservation experts, this new approach allows the public and energy specialists to also play a role,” said Prof David Coley, lead researcher and Professor of Low Carbon Design in the University of Bath’s Department of Architecture & Civil Engineering.

“It doesn’t attempt to bypass the history of a building, but brings together energy modelling and structured discussions with the public to allow conservation officers and others to discover where there is no conflict, and to establish whether their views are in line with the energy facts and with public opinion,” he said.

The researchers at Bath are now looking to work with local authorities and other organisations to test out the approach, ‘A socio-mathematical approach to exploring conflicts between energy retrofit and perceived heritage character’. The paper was published in Building and Environment at https://www.sciencedirect.com/science/article/pii/S036013231830180

The University will help to both design the project and analyse the results to help reduce carbon emissions via Prof Coley at d.a.coley@bath.ac.uk 

Nick Flaherty