We are collaborating with Heatherwick Studio to design a pastoral cancer care centre at St James’s University Hospital in Leeds. This unique project comprises three ‘pot’ structures with branching timber fins that support a heavily landscaped roof.
The project originally took its inspiration from plant pots, providing a green respite from the surrounding hospital environment, visually distinct and welcoming for both patients and visitors.
The site was previously used as car park, but later left as a steep slope with light planting and trees. This made ground was significantly deep, and the poor structural quality of the underlying soil meant that particular attention was needed on the substructure design. The confirmed presence of landfill gases is also a significant risk to the project both during and after construction.
A multi-storey car park which serves St James’s Hospital neighbours the site, and the importance of leaving its foundations undisturbed during excavation had to be considered.
The foundation will be a shallow raft with steps to facilitate the change in ground level across the site. This approach reduces the amount of excavation required and will need retaining wall elements, providing additional stiffness. The raft will also allow gases released from the made ground to be ventilated effectively and safely. The steep site means that additional retaining will be required to support the surrounding 4.5 m-high landscaped area, for which a gabion retaining wall is considered the best solution.
The superstructure comprises three small structures, referred to as ‘pots’, with branching roofs to create central circulation spaces intersected by glazing. The pot walls, suspended floors and roof slabs will all be constructed using timber stressed skin diaphragms with embedded steelwork where enhanced strength and stiffness are required. Where the roof slabs support landscape, they will be topped with 100 mm of concrete, which, together with the weight of the soil and trees, will provide the primary load acting on each pot.
Cancer care centre in Leeds comprising a trio of interconnected timber pots with landscaped roofs
Maggie's Cancer Caring Centres
£ 4.1 million