The Confetti Campus HQ is a six-storey building housing teaching spaces for 700 students, a café, library and roof gardens. The corner site is surrounded by three conservation areas, and its boundaries are marked by the gable ends of two Victorian industrial buildings, also used by Confetti.
Caves have been a feature of life in Nottingham for over 1700 years, with hundreds of caves still present, many of which undiscovered. A desk study and borehole investigation indicated there were no known caves beneath the site, and so the pile layout was designed on the assumption that there were none.
As the existing building was demolished, an archaeological dig discovered a series of cave chambers over 700 years old, described as the "most significant to be excavated in the city centre in over a decade". The caves, directly beneath the proposed building, measured 15 x 9m in footprint and up to 7m below ground. We rapidly redesigned the foundation and ground floor and in doing so ensured the caves could be preserved while avoiding delay or additional cost to the main contract.
Following a full survey, the caves were carefully filled with crushed recycled aggregate to allow safe access of the 40-tonne piling rig. To optimise usable space, the upper floors were extended out beyond the ground floor footprint over the pavement below. A 600mm thick Reinforced Concrete cantilevered transfer slab was designed at first floor level. The flat slabs of the floor structures above were supported by columns within the outer façade. These were carried by the transfer slab at first floor level, which cantilevered over the ground floor edge columns.
Confetti Campus HQ has transformed the wider Confetti site, allowing the client to optimise the use of the existing historic buildings while uncovering and preserving significant archaeology which is a crucial part of the Nottingham city centre heritage.
The project has been BREEAM Certified "Outstanding".