The proposals involves 2000sqm commercial basement extension to Hardwicks Grade II* Listed ‘Great Hall and Library’ Buildings on a historical site.
Two standalone double basement structures extend below the water table and into the London Clay stratum. The buildings are designed to resist buoyancy and heavy pressures from the ground water and expansion of the clay layer below. A 7m tall frameless glass link structure provides the connection frThe East Terrace extension is an entirely subterranean development comprising two basement levels and a feature rooflight extending the length of the terrace level whilst the Library extension comprises two storeys of office space above ground.
The superstructure comprises a concrete frame from first floor level downwards with contemporary masonry and stone cladding reflecting the existing victorian aesthetic.
The basement structures will be formed using secant piled retaining walls and internal concrete box construction.