Commercial
Pre-let success
22 NSC
February 18
The latest steel-framed building to
top-out at the large King’s Cross
development is Building S2, situated
on Handyside Street. Already
fully let, the 12-storey building will offer
23,000m2 of space and is set to achieve a
BREEAM ‘Outstanding’ environmental
rating.
The King’s Cross redevelopment
programme is radically changing a former
run-down industrial site in central London
into a vibrant business and residential
neighbourhood.
Described as one of the largest
regeneration schemes in Europe, it will
include 50 new buildings, 2,000
new homes, 20 new streets
and 10 new public
squares
spread over 67 acres.
Steel construction is playing a significant
role within this development with a
number of commercial and retail schemes
having already made use of the material’s
programme benefits.
Building S2 has reaped the rewards of
a design change from a post-tensioned
concrete frame to a steel frame. The initial
design had the building based around a fairly
tight structural grid, which was later deemed
to be too constrained with too many internal
columns for modern office requirements.
“The design was changed to a steel
solution because the material offered a more
economical method to achieve the desired
spans and service integration,” explains
Ramboll Engineer James Clay.
Another benefit of steel from a design
perspective was in framing the numerous
architectural set-backs and cantilevers,
primarily the west façade, south set-back
terraces and a south-east cantilevered
corner.
Steel allowed the project team to hang
parts of the floorplate and transfer other
areas without impacting on the floor-toceiling
height or raised access floor zone,
which would not have been possible in posttensioned
concrete.
Sat atop a concrete basement substructure,
the building’s steel frame starts at
ground floor level and is based around a 12m
× 12m grid with structural stability derived
from a centrally positioned concrete core.
Fabsec cellular beams have been used
throughout to accommodate ductwork and
services, and these members also support
metal decking and a concrete composite
flooring system.
As well as accommodating the services
within their depth, and consequently
maximising the building’s floor-to-ceiling
heights, the cellular beams will also be left
exposed within the completed project,
giving the tenant its desired raw, modern
industrial-like environment.
The ground floor of S2 is a double-height
space containing the main entrance lobby,
restaurants and retail units. Above, the first
floor has a cut-out area that overlooks the
entrance. From the first floor to the ninth
level, the floors are fairly repetitive with only
a single row of internal columns disrupting
the open-plan space.
A steel-framed solution was the answer for the latest standout
commercial development in London’s King’s Cross. Martin
Cooper reports.
Two atriums are
positioned either side
of the core
Steel has allowed
cantilevers and
architectural set-backs
to be incorporated
into the design
/Sustainability#Understanding_BREEAM
/Construction
/Retail_buildings
/Concept_design#Floor_grids
/Service_integration
/Facades_and_interfaces
/Concept_design#Structural_options_for_stability
/Concept_design#Concrete_or_steel_cores
/Steel_construction_products#Decking_for_floors
/Floor_systems#Composite_slabs
/Floor_systems#Composite_slabs
/Steel_construction_products#Cellular_beams