Three types of Kawneer's curtain wall feature on the Atlas' commercial element.
Bespoke curtain walling by leading UK manufacturer Kawneer was preferred for an 11-storey office building at the heart of London's architectural sector.
Kawneer's AA®265
unitised system was adapted by the company for the commercial element
of the £200 million Atlas building - at 40 storeys the tallest tower in
London's Tech City area - at 145 City Road, Clerkenwell.
Concept-designed
by Make architects and delivered by the Design Delivery Unit of Scott
Brownrigg, the commercial building actually featured a total of three
types of Kawneer's curtain walling - the traditional stick system AA®110 (zone drained) on the ground floor, the adapted AA®265 on the floors above, and standard unitised AA®201 on the tenth floor return elevation to the existing building.
The adapted AA®265
modular system incorporated GRC and aluminium rainscreen cladding and
glazed vision areas in each panel. Some 3m wide, 3.85m high and one
tonne in weight, each unit was delivered to site and hoisted into
position by a tower crane, complete with the cladding and glazing in
place.
Kawneer's Technical Proposals Engineer Dave Fletcher said: "The basic AA®265
design was revised to accommodate the building movement that had been
identified by the structural engineers as it could accommodate the size
of units and the GRC rainscreen units being pre-fixed to the panels.
"The
system developments, including new profile and accessory design such as
19 project-specific dies, were all carried out by our Technical
Department at our Head Office."
Installed
by specialist sub-contractor Mace Facades for main contractor Mace, the
Kawneer systems also included thermally superior AA®720 entrance doors on all floors.
The
Atlas' commercial element is occupied by WeWork and features a strong
emphasis on nature, with three roof terraces and external green walls.
WeWorks'
coworking space allows members to enjoy 11 floors of collaborative work
spaces, stunning private offices, welcoming event spaces, and modern
conference rooms for hosting key client meetings. In addition to being
dog-friendly, this super-accommodating office space features bike
storage and on-site showers.
Along
with the Atlas tower, the WeWork building sits above the London
Underground and Thameslink lines. This discovery at planning stage
changed the concept for the structural strategy, resulting in the
creation of a new superstructure design to prevent the buildings from
twisting and leaning.
Loads
imposed by the buildings are kept clear of the tube tunnels by
cantilevering the structures over the subterranean Victorian
engineering. The mass provided by the frame, and by increasing the
thickness of the ground-floor and mezzanine first-floor slabs, helped
give the structure sufficient inertia to dampen the ground-borne
vibration from the underground trains.
The
original planning concept was for a series of white and off-white
shades of terracotta cladding. However, with the stability issues raised
at post-planning, the weight of the terracotta posed a challenge with
the cantilevered building.
Design
Delivery Unit at Scott Brownrigg demonstrated options that could be
achieved using anodised aluminium, and following modelling and testing
of the material, proved that given the scale, repetition and shape of
the facade, a unitised system would work and still achieve the original
vision.
