Embarking on a project to refurbish its New Court Building, Trinity College decided to focus on sustainable accommodation rather than the traditional refurbishment of a grade 1-listed building. New Court is located in the centre of Cambridge, on the Backs of the River Cam and adjacent to the Wren Library.
Dan Thomas who led the project on behalf of Bidwells, says: “Many Oxbridge colleges view the listed status of their building stock as a prohibiting factor when considering the incorporation of sustainable features. However, this was a project with a difference. The design team identified a combination of sustainable technologies that could be incorporated, whilst remaining completely sympathetic to the listed fabric and features.
“We needed to refurbish 140 rooms and achieve an 80 percent reduction in carbon consumption, as well as reduce running costs. The college also looked closely at the maintenance strategy, taking a longer-term view of 30-35 years.
“Clearly a highly strategic approach was needed to achieve these objectives, as well as a robust and fully integrated building monitoring and control system. The timescale was also tight – we started on the project in January 2014 with a deadline of September/October for the rooms to be ready for the students returning.
“The external walls, although thick, did not help retain heat and some of the existing dormers and windows did not fit as well as they could and were draughty. As a result of the fabric, the heating system was run almost constantly through the year delivering uneven heat in different areas of the building.
“With a team of specialists including Cambridge-based 5th Studio Architects and Cambridge Architectural Research, together with Trinity’s junior bursar Dr Rod Pullen, we put together a plan which incorporated a range of sustainable technologies and features to meet the objectives.
“These included ground source heat pumps linked to high-efficiency underfloor heating in all rooms, providing even heating across the entire space, improving comfort, reducing point heat losses and allowing greater flexibility in the positioning of furniture.
“Other features included the installation of photovoltaic cells on existing roof slopes, enhancement of the building fabric to achieve much greater air tightness and putting in a mechanical ventilation heat recovery (MVHR) system to provide constant ventilation to rooms which had been enhanced to be more airtight.
“We also insulated the walls and refurbished the existing double and triple glazing with a specialist glazing system used in the restoration of historic buildings to enhance energy efficiency, but maintain the historical profile. This slim-line glazing was chosen from 15 possible options which were researched and tested for internal and external appearance, operation, reliability and maintenance, as well as thermal performance.
“In addition, energy-efficient lighting was installed throughout, with new power and data cabling accommodated within built-in furniture elements to allow maintenance access for future adaption, rewiring or repair and avoiding the need to ‘chase’ into the historic walls.
“This has been a challenging project but is set to achieve an 80-88 percent reduction in carbon emissions (including CRC energy-efficiency levy), a feat that has achieved widespread recognition. Not only will the energy-efficiency measures improve comfort, usability and sustainability, they also will result in projected financial savings over the coming years.”