The Kantor Centre of Excellence provides clinical, research and training facilities and office space for the Anna Freud Charity, as well as teaching space for the Pear Family School, a new specialist school for children with mental health problems.
The new build and refurbishment scheme is located on a tight central London site near King’s Cross. The new structure wraps around an existing chocolate factory dating from 1915 and incorporates a double basement and two storeys at the rear and a single basement and six storeys at the front.
Webb Yates Engineers, in collaboration with the architect and building services engineer, conceived a composite timber and concrete structure.The design provides an integrated solution that utilises the lightweight and low carbon qualities of timber while taking advantage of the high compressive stiffness, fire resistance, strength and thermal mass of concrete.
The existing structure was extensively reconfigured to meet the needs of the brief. Double height spaces were created between existing floors, openings were formed to connect the new and old buildings and an existing masonry stair core was replaced with RC slab infills, with a new stair core built in an alternative location.
The new structure comprises a concrete frame from basement to first floor, with exposed columns, shear walls and exposed in-situ RC slab. From the first-floor up to the roof level the concrete slab creates a plinth which supports a beech GL70 laminated Veneer Lumber (LVL) frame combined with timber concrete composite (TCC) floors. To achieve the composite action, the timber elements were erected and propped before landing the precast planks. M12 coach screws were then installed into the top of the joists, to act as shear connectors, before in-situ concrete stitches were cast to form the shear connection between the elements, completing the composite.
Extensive research and testing into materials and connections resulted in a holistic final solution which is structurally and thermally efficient. The scheme is due to achieve a BREEAM Excellent rating, narrowly missing out on an Outstanding score.