The Spencer Building at Corpus Christi College demonstrates ambitious sustainability targets delivered through conservation-led design, forensic engineering and a retention-first strategy on a constrained site.
The building provides 479m² of additional library and study space for one of Oxford’s oldest colleges, whose Special Collections include more than 20,000 early printed books as well as many manuscripts. The site presented significant constraints: a narrow six-metre access to the north and a complex network of listed and unlisted historic structures both around and below the site.
Alan Baxter’s approach was founded on retaining and working with existing fabric wherever possible. Existing masonry facades, medieval boundary walls and twentieth-century foundations were incorporated into the new building, reducing excavation, concrete use and waste disposal while preserving the character of the historic setting.
Detailed investigation of the site’s layered archaeology, foundations and ground conditions allowed the lightweight steel-framed library to sit on existing foundations, with the plant room remaining largely within the previous basement footprint. A demountable steel frame, timber floors and blockwork used in place of reinforced concrete walls embedded circular economy principles into the design, supporting adaptability and future reuse.
Thermal separation between new structure and retained masonry was carefully detailed, with fixings providing lateral restraint without creating significant thermal bridges. Internal insulation, high-performance glazing and the use of existing thermal mass supported a low-energy internal environment. The building meets Passivhaus requirements, with airtightness of 0.6 ACH at 50Pa and a predicted peak heating load of 10 W/m². Total operational energy use is reported as 15 kWh/m²/year, aligning with the pilot version of the UK Net Zero Carbon Building Standard.
The project won the RIBA South 2026 Award and was shortlisted in the Legacy and Heritage category at the 2025 OxProp Awards.
Structural Engineer: Alan Baxter