Architect and Builder Magazine South Africa March/April 2015 | Page 43

on this floor. The approximate GLA for each level
varies from 1,780m2 on the ground floor to about
2,769m2 for first to fourth floors and 1,982m2 for the
fifth floor, with a further 2,618m2 in basements.
Building Geometry
The building geometry is developed around a
central core comprising four destination control
lifts, one fireman’s/goods lift (linking all levels
including all basement levels), and two fire escape
and circulation stairs, ablution facilities including
mobility impaired ablutions in both male and female
ablutions, a janitor’s room and a tea kitchen.
There is further provision for two pause areas
adjacent to an escape stair on each level. Two
dedicated areas for bulk filing are provided
adjacent to the core. The surrounding floor plates
are of varying floor depth from 12m to 27m to allow
for flexibility in the space planning design.
Façade
Fenestration on the façade is limited to certain
areas to allow for enough natural light in an open
plan office environment, while reducing the amount
of exposed fenestration on the south-western and
north-western façades. There is sun screening on
the north-western and north-eastern façades. The
structural grid for the building is 8,4m x 8,4m.
The roof comprises a waterproofed structural
concrete slab to allow for accessibility and to
accommodate the HVAC plant.
Exterior Finishes
The exterior of the building is finished in natural
stone, Versus wall coating and curtain walls

Acacia House

designed to withstand wind loads expected on the
ridge as well as offering the performance figures
required to meet with building design.
Access and Parking
The building is positioned on the north-western side
of a terraced podium / garden space. Total parking
in the basement is approximately 748 bays providing
4,6 bays/100m2 of rentable office space. Access to
the building is managed via two shuttle lifts linking
all basement levels to the building lobby. Four lifts
serve the office floors. All electrical plant, delivery
areas, combined waste sorting and holding areas
and change room facilities are located in dedicated
areas in basement -4 with the sprinkler protection
and potable water plant located in basement -4,
beyond the extent of parking to the perimeter of
the site.
Engineering
The project started with bulk earthworks to create
four parking basement levels below Umhlanga
Rocks Drive. The large basement was formed with
soldier piles around the perimeter of the building
and 50,000m3 of soil was carted off site. Skin friction
augured piles were installed with an average length
of 18m into the Berea Red supporting soils.
A fast track construction program was
implemented to meet the stringent time lines to
hand the building over to FNB on time.
The total building area is 38,000m2 over the four
basements parking levels and six office floors. An
8.4m by 8.4m column grid was used and the structure
mainly comprised pile caps, reinforced concrete
columns, shear walls and post-tension flat slabs. At

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