This project sets new standards for energy-efficient office construction and operation. It is one of the first to use recycled concrete aggregates for the in-situ concrete and has been designed to maximise the potential of natural ventilation.
The building has a unique wave floor construction. This allows air to be drawn through the structure naturally and acts as a folded shell resulting in minimum use of materials. The floor is stitched to precast-concrete trusses with an in-situ topping. To speed construction and ensure a quality finish, precast concrete was specified. In order to reduce the amount of transportation required, the number and size of the units were minimised and complemented with in-situ concrete.
The precast omnia-type elements with composite in-situ floors offer the benefits of both precast and in-situ concrete. The in-situ elements also provide diaphragm action and provide an acoustic and fire barrier.
Precast panels to the top of the air duct form a fire and acoustic separation and support the raised floor. The tops of the wave are cooled by borehole water, with pipes cast into the floor screed. The wave is reflected in the edge truss, as the wave forms natural web members of a truss. By including a top and bottom member to the web, truss action is achieved. The open web structure of the truss also allows the flow of air.
The precast-concrete edge trusses were cast on their sides with integral steel channel members to the top and bottom booms to facilitate bolting to steel columns. The in-situ concrete to the wave floor provides support between the main floor and the edge truss. The in-situ stitch between the precast floor units and beams also allows for construction tolerances between various precast components. Precast-concrete stack elements to the south facade pull the air through the building on still days.
The quality of the precast-concrete works carried out by Structural Concrete Contractors is outstanding, and the positive attitude of the main contractor, Sisk, quickly addressed the buildability issues. The speed of construction was on a par with a typical office floorplate.
OWNER Building Research Establishment
ARCHITECT Feilden Clegg
CONSULTING ENGINEER Buro Happold
BUILDING SERVICES ENGINEER Max Fordham and Partners
MAIN CONTRACTOR John Sisk and Son
FORMWORK, REINFORCEMENT AND IN-SITU CONCRETE WORKS Colohan
READY-MIXED CONCRETE rmc uk
CEMENT Rugby Cement
PRECAST CONCRETE Structural Concrete Contractors
HOLLOWCORE FLOORING Bison Concrete