The project involved creating new sports facilities and formed part of a wider masterplan for King's College School. The new facilities form a set of three linked pavilions; a six-court sports hall and 25m six lane swimming pool sandwiching a central pavilion housing changing areas, aerobic studios and strength and conditioning rooms.
The central pavilion is a double-height in-situ reinforcement concrete (RC) frame and contains the sports centre reception and changing rooms at ground level with viewing galleries, an exercise suite, a strength and conditioning area and aerobics studios above. Significant areas of the RC frame are exposed and provide visual fair faced concrete walls and soffits. A ground granulated blast-furnace slag (GGBS) was used in the concrete mix as a cement replacement to lower its carbon content, but to also provide a light coloured concrete.
The swimming pool hall is glazed on three sides and features a sweeping curved green roof to help lessen the visual impact of the building where it meets the boundary. The curve raises up to meet the central pavilion and continues to link the building forms. Curved glulam beams, with Cross-Laminated Timber (CLT) panels span between them, responding to the roof profile of the pool and providing a durable structure suitable for a pool hall environment. The glulam beams span between the roof level of the two-storey pavilion and down to a series of single storey height exposed curved, chamfered and tapered RC columns.
The column heads are linked with an RC beam which creates a sway-frame and helps provide stability to the roof structure. Bespoke cast-in galvanised connectors provide concealed supports to the glulam structure. The pool box sits within a larger basement which provides plant space, access for maintenance and acts as a plenum to deliver fresh air to the pool hall. The basement and pool box were built using in-situ RC designed to BS8007 to limit crack widths and formed using concrete-resisting additive to provide a water-retaining structure.
The sports hall uses a steel frame and ties, and links back to the central pavilion. A primary tubular steel truss runs centrally across the sports hall roof which supports secondary tapering triangular tubular warren trusses; these sit centrally between the sports courts below and align with the positions of linear roof lights to provide natural daylighting into the hall. Structural linear trays form the roof deck and support photovoltaic panels. The roof structure has been designed to support sports equipment, removing the need for secondary steelwork. Braced steel columns support the roof structure, with precast concrete wall panels spanning between the columns to provide a flush and robust finish to the sports hall. The walls provide restraint to the outer brick cladding which includes a rotated brick bond.
A link building wraps around the façade of the existing sports buildings to seamlessly tie the new and old together. This area provides a new landscaped courtyard at the entrance, with level access from the main road created using precast retaining walls installed against existing structures to allow the ground levels to be raised. Beneath the courtyard is a large attenuation tank to store surface water before discharging it back into the public sewer.
The demolition of the rifle range and all-weather tennis courts created space for the footprint of the new sports building. The old swimming pool was also demolished and replaced with six floodlit tennis courts and three new cricket lanes at the southwest corner of the school campus.