Structural insertions threaded throughought in this complex, extensive reconfiguration and restoration of the historic Victorian Gothic buildings with a new build addition.
Rick Mather Architects
Mansfield College, Oxford
This project has transformed the main communal and service spaces of the College and required a comitted collaboration from EOC as structural engineers, and other members of the team, to resolve complex details throughout the project in order to succesfully realise the requirements of the brief.
Currently one of the smallest of the constituent colleges which make up the University of Oxford, it was founded as a Non-conformist theology college in 1886. The original College buildings were amongst the finest works of the important Victorian architect Basil Champneys, and designed in the 'collegiate gothic' style. Since then the College has continued to expand in student numbers and must now re-address its growing needs.
The increase in student numbers demands a corresponding increase in catering, dining and bar facilities. As part of this work, the Champneys East Range buildings have been extensively re-designed to accommodate these facilities. This involved many structural interventions in the sensitive historic fabric of buildings which had shown evidence of past structural movement and the site has a high water table. A thorough investigation of the structures and foundations of the existing buildings was undertaken to inform decision-making.
The quadrangle garden has been discretely dropped in level to form a terrace adjacent to a new café within the existing envelope. This required extensive temporary works to support the existing masonry structure above, including rubble filled ashlar stone walls, whilst the new structure was inserted in order to open up the existing spaces.
New openings were made in the dressed ashlar walls, and windows were extened to become doors, sometimes requiring hidden steel lintel strenghtening to maintain the gothic detailing.
A new building provides foyer and circulation spaces as well as the new college kitchens. This is rc framed on an rc raft foundation to create a complicated series of spaces to meet the programme of the College. This building is built against the historic chapel and the East Range buildings but is structurally separate from both so that differential movements can be accomodated.
Extensive structural glass insertions were also made, including a large rooflight over the foyer, supported on a lightweight stainless steel frame. This cantilvevers out from the new building without taking any support off the gable wall of the East Range, to allow building movements to occur.
A new steel stair and glass lift meet a thin steel cantilevering mezzanine to make the centrepiece of the foyer space.