Commercial
The City’s
dramatic
addition
Eventually reaching a height of 190m, 52 Lime Street is the
City of London’s latest standout commercial development.
Martin Cooper reports.
14 NSC
Annual Review
Featuring a dramatic architectural
shape with asymmetric facets and
a pointed attic roof structure, 52
Lime Street has from its inception
been dubbed the Scalpel, a name that has
since been adopted as the official moniker.
Joining a cluster of other prestigious
high-rise buildings in the square mile,
the project will offer 36,966m2 of internal
floor area over 35 office floors, retail and
restaurant areas.
Designed by architects Kohn Pedersen
Fox, the project also includes a public
square. The realm may also provide
space for public art and tables linked
Reaching new
heights: Steelwork
nears completion
FACT FILE
52 Lime Street, London
Main client:
W.R Berkley Corporation
Architect:
Kohn Pedersen Fox
Main contractor:
Skanska
Structural engineer:
Arup
Steelwork contractor:
William Hare
Steel tonnage: 10,500t
Cost also plays an important role in any
construction project and the use of a BIM
model on this scheme has helped the team
ensure the steelwork frame is as efficient
as possible.
“We’ve made a considerable weight
saving as all of the beams have varying
flanges and webs depending on the relevant
loadings,” explains Arup Project Engineer
Steve McKechnie. “All of this was worked
out automatically via the BIM model.”
Having taken possession of the site once
the demolition of the previous building
to ground floor level had been completed,
Skanska’s initial task was to complete the
basement works prior to the steelwork
erection starting.
A third of the existing basement was
partially deepened and, to keep the
construction programme on schedule,
the ground floor slab was cast early. This
allowed the basement construction to be
done in a top-down method, while the
steel erection was able to carry on above
simultaneously.
Early works also included constructing
the building’s main concrete core. Once this
had reached its halfway point at level 17, the
steel erection programme was kicking off at
ground floor.
Unlike many commercial buildings, the
Scalpel’s main core is offset and positioned
along the south elevation, which provides
shade from solar gain. In this way, the
structure’s available floor space has been
maximised and internal spans of up to 20m
have been achieved.
to a specialist ground floor coffee shop,
designed as a nod to the 17th century
establishments that acted as meeting houses
for London’s fledgling insurance market.
Setting it apart from its neighbours,
the Scalpel features an inclined northern
façade, which has a diagonal fold line
running from top to bottom giving the
building its distinctive look and name.
This façade is formed with a series of
cranked plate girder columns, spaced at
6m centres. For the double-height ground
floor these columns are vertical, but
from the first floor they are cranked and
slope inwards all the way to the building’s
pointed top.
Elsewhere, the structural frame consists
of a composite design with steelwork
supporting metal decking and a concrete
slab. All of the floor beams are 670mmdeep
fabricated plate girders with holes in
the web to allow service integration within
the structural floor zone.
Commenting on the decision to use
a steel framing solution Skanska Project
Director Ian Perry says: “Using steelwork
is an efficient option for this type of
construction project as buildability and
speed of construction are vital on a city
centre job.”
The building has a
dramatic inclined
northern façade