The project provides new residential accommodation, for St John’s College Cambridge, to serve both students and academic staff with 39 new townhouses arranged around shared gardens, providing 245 study bedrooms in total. The scheme includes a standalone Porter’s Lodge, extensive landscaping and a new lane which connects Wilberforce Road to Herschel Road. The Client’s brief required high quality and sustainable buildings that are flexible and durable in use, efficient in terms of space and energy, cost-efficient to run and maintain, and designed and constructed to achieve Passivhaus Certification. The project was procured under a single stage tender for a JCT Design and Build Contract.
The form of construction for the townhouses incorporates piled foundations and thermally broken insitu reinforced concrete slabs, CLT super-structures with CLT window frames and pitched roofs with dormer window insertions, high performance windows and doors, facing brickwork cavity walls, hung clay tiled facades and roof coverings. The design uses CLT as the primary structure to provide a very robust airtightness line, incorporating high levels of insulation and minimising thermal bridging, to achieve Passivhaus performance criteria. Heating and hot water are provided by air-source heat-pumps. Photovoltaic panels are located on selected south facing roof slopes with diverters to divert electricity generated to the heat-pumps. Ventilation and heat recovery (MVHR) is provided with a series of chimneys serving as sources of intake and extract. The highest levels of quality control were employed to ensure construction details did not compromise the air-tight line and internal finishes; external facades and landscaping achieved the design intent.
Photo Credit: Fred Howarth
