Residential
NSC 13
February 18
founded on the basement’s concrete
retaining wall. Stability is derived from a
combination of concrete lift and stair cores,
and bracing.
Explaining the choice of framing
materials, Harley Haddow Director
Richard Dunn says during the early stages
of the design process a cost analysis was
undertaken and steel was the most costeffective
option.
“There is a planning restriction on how
high the terrace can be, and so we went
for a steel-framed solution supporting
precast flooring as it offered the best way
of maximising the project’s floor-to-ceiling
heights, as the planks are set within the floor
beam’s depth.”
The terrace is neatly split into two
structurally-independent frames, each
approximately 100m-long, by a centrallypositioned
car park ramp and a concrete
plant house.
BAM Project Manager Gary Brown says:
“We are working on a phased construction
programme that will see the western side,
which is currently under construction,
handed over in July.
“We will then decamp from the site and
return early in 2019 to construct the eastern
end of the terrace.”
BAM began the initial phase during
April 2017 and early works included the
excavation of the car park. Following the
entire arc of the terrace, the 4m-deep
basement required nearly 40,000m3 of
overburden to be removed from site.
Steelwork contractor Hescott Engineering
completed the western part of the terrace
in January (2018), and this work required
1,000t of steel. The company was also
responsible for the installation of precast
flooring and stairs.
Hescott used two 50t-capacity mobile
cranes for the steelwork erection and a
further two 100t-capacity cranes for the
installation of precast units. An identical
procedure will be employed when the
company returns to site for the eastern end
of the terrace.
Using a variety of MEWPs in conjunction
with its cranes, Hescott had to contend with
extremely confined site conditions. With
only a slither of land available between the
terrace and the former college building,
there was very little space for materials
storage and so all steel and precast units
were delivered on a just-in-time basis.
Generally, Hescott erected the terrace
building up to and including second floor
level, installed the precast stairs and floor
planks, before finally erecting the uppermost
penthouse level.
The steel frame is set out on a regular
7.2m × 6m grid pattern, with two internal
rows of columns. There are no curved
The second floor flats
have mezzanine levels
Steel contractor
Hescott erected
steelwork and installed
precast planks
14
The three-storey
terrace will sit behind
the renovated
Donaldson’s building
/Concept_design#Structural_options_for_stability
/Floor_systems#Precast_units
/Construction
/Construction#Steel_erection
/Construction#Mobile_cranes
/Education_buildings
/Concept_design#Floor_grids