Spencer Building, Corpus Christi College, University of Oxford

Heating and cooling for the library and archive are provided by ground-source heat pumps via four boreholes in the car park. The library and the archive, though housed in the same building, have different environmental requirements. 

The library uses a hybrid ventilation strategy, with mechanical ventilation with heat recovery (MVHR) providing reliable low-energy ventilation in winter, combined with natural ventilation with openable windows and automatically controlled rooflights during the summer.

The archive requires very specific conditions, which are largely passively maintained. Additional mechanical cooling and humidity control are utilised when needed during the hotter summer months. Mechanical ventilation is run briefly at night to refresh the air, maintaining a tightly controlled climate suitable for the preservation of the archive and the special collection.

The Passivhaus standard was chosen to minimise energy use, provide a stable temperature throughout the building, and control temperature and relative humidity within the archive. Alongside qualitative advice, the Passivhaus energy model, Passivhaus Planning Package (PHPP), was used from the early stages to develop the design in coordination with the architect and the rest of the design team. We then provided support to the team through detailed design development, and worked closely with them and the main contractor through construction.

An airtight concrete structure was designed against the City Wall, with the wall’s thermal mass moderating the temperature naturally, along with extensive insulation and high-performance triple-glazed windows. 

The acoustic design for the library delivered appropriate sound insulation to enclosed rooms, ensuring privacy where required. In addition, the controlled reverberation character of the spaces and robust noise control of mechanical services, which meet all Passivhaus noise criteria, ensure a comfortable acoustic environment for the users.

The passive approach and low-energy MEP design, using ground-source heat pumps for heating and cooling, mechanical ventilation with efficient heat recovery, and roof-mounted photovoltaic panels, means that the all-electric building requires minimal space heating. The total energy demand is projected to be just 15 kWh/m² per year.