Ruth Deech Building, St Anne’s College.

Oxford’s stone-clad streets, gables and gothic windows provide both a strong backdrop and an element of aesthetic restriction for any proposed buildings; contemporary structures, such as the new Ruth Deech Building in St Anne’s College, must be sympathetic to their surroundings, adopting appropriate forms and materials.

Location

Oxford, UK

Client

St Anne’s College

Architect

KPF

Project Value

£ 8.5 million

Floor Area

5,000 m²

Status

completed 2005

Expertise

Structures

The 5,000 m² mixed-use building brings together 110 high-quality student bedrooms, each with a balcony, a porter’s lodge and dining facilities as well as a lecture theatre for up to 100 people, in a four-storey structure with basement. The elevations are finished with Bath stone mullions and inset oak cladding in tune with its leafy surroundings, with glazed lift cores extending to above the height of the roof.

Set in former residential gardens, the size of the site and its proximity to the college presented some initial buildability issues, such as limited site access via a cul-de-sac, possible clashes with examinations and a need to minimise dust and noise for the students living in that environment. These factors, as well as the installation of prefabricated elements such as ‘shower pods’, were all phased and incorporated into a complex and detailed construction programme.

With this in mind, we specified a raft foundation, negating the need for an expensive and labour-intensive suspended basement slab, and simplifying both the construction sequence and the earthworks contract. For the superstructure we developed an RC frame, using cross walls to provide lateral stability and to provide support where the first floor steps out. This also allowed us to use steel staircases which could hang off the concrete slab without the need for intermediate support.

In terms of the floor slabs, an Omnicore plank system provided a working platform and reduced the amount of formwork needed. We minimised the concrete and therefore the weight of the floor planks by introducing light polystyrene blocks at regular centres.