FE ATURE
ASB North Wharf’s activity-based working set-up includes quiet rooms and open collaboration lounges.
A sense of
excitement
The design of ASB North Wharf in Auckland, New Zealand reflects the desire of its tenant
for a world-class building that places staff and customers at the centre of the sustainability
equation. Sean McGowan reports. Photography by John Gollings courtesy of BVN Donavan Hill.
Demonstrating and quantifying value
from good indoor environmental quality
(IEQ) design has always been something
of a challenge.
Sure, pre- and post-occupancy
evaluations can be conducted, and case
studies can be pored over. But convincing
a client to embrace the IEQ imperative
from the outset of a project is another
scenario altogether.
So when architect BVN Donovan Hill was
engaged to design its third building for
New Zealand’s first savings bank, ASB, it
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E CO L I B R I U M • D E C E M B E R 2 0 1 3
must have been encouraging to receive
an aspirational brief that put staff front
and centre.
The building is
’
designed for people
Located on the Waitemata Harbour
waterfront in the new urban centre of
the Wynyard Quarter in Aukland, the
seven-storey office block consists of two
buildings punctuated by Waikokota Lane,
which provides 24/7 pedestrian access
to the waterfront.
Architecturally, the fully glazed and
transparent walls of the lane provide a
visual and material break in the long
northern façade, while creating a visual
connection between building occupants
and the public below.
Viewed from the harbour, the two
buildings also appear separate due to the
different façade treatments used on each
one. The north façade’s design references
the leaves of the native Pohutukawa tree.
FE ATURE
BOATHOUSES AND
NEIGHBOURHOODS
Internally, the building is designed
to maximise access to daylight, views
and fresh air (dependent on weather
conditions) – all of which promote the
health and well-being of the occupants
and feed into the brief calling for
exceptional IEQ.
Two types of workspaces are provided:
the public spaces referred to as
“boathouses” and free working spaces
known as “neighbourhoods”. The latter
are made up of 15 different work settings
– from quiet rooms known as “cockpits”
to open collaboration lounges.
The design of an exposed
“The building is designed for people,”
says Brian Clohessy, practice director
for BVN Donovan Hill.
services scheme that
“Light-filled spaces of varying scales
and materiality create a sense of
excitement and drama for the users.
The atria throughout the building form
a transparent environment, increase
daylight, promote natural ventilation
and create an internal community
focused on the business of the day.”
performance and project
An activity-based working (ABW)
environment was designed as part
of the fully integrated fit-out. Espousing
a basic design tenet of “democracy”,
there are few restrictions on which
areas staff can access.
meets the engineering
budget – as well as the
aesthetic objective – is
a challenge not to be
’
underestimated.
“Choice is a fundamental driver of the
design of the workplace,” says Clohessy.
“Tenants can choose to sit by a view,
outside on the decks of the portals, near
an open window, at the base of a void
– or they can track sunlight around the
building during the day. In essence, they
control their local environment based on
the decision of where they sit within the
building.”
The colour coding and themes used
on each floor take their cues from the
nautical environment outside.
WORDS INTO ACTIONS
A long-standing relationship with BVN
Donovan Hill helped Arup secure an
invitation to provide multi-disciplinary
engineering services for the project. The
architects felt Arup understood what it
took to realise their vision for the project.
Working closely with ASB’s head of
property services, Alan McKenzie (a
mechanical engineer himself), Arup was
able to deliver its IEQ design response
with full buy-in from the tenant.
“In our discussions with Alan and other
stakeholders, we explained our view that
the trend for improved IEQ is already well
established in high-quality commercial
office projects,” says Alex Baidjurak, Affil.
AIRAH, mechanical engineer with Arup.
The north façade shading
takes design cues from the
leaves of New Zealand’s
D E C E M B E R 2 0 1 3 • E CO L I B R I U M
native Pohutukawa tree.17
FE ATURE
North Wharf’s funnel was constructed by a local boat builder, and delivered via barge along the waterfront.
He says at ASB North Wharf, IEQ, staff
health and well-being were considered
from the outset of the project, without
the constraints of Green Star.
Light-filled spaces of
varying scales and
materiality create a sense
of excitement and drama
’
for the users
“Our task was to provide exceptional
levels of IEQ compared to other projects
within the Australasian region and
abroad,” Baidjurak says. “Our ESD
and mechanical engineers took a ‘first
principles’ approach and studied the local
environment in order to inform the IEQ
solution.”
This work established early on that the
local climate would allow for the capacity
to supplement mechanical ventilation
with fresh air via openable windows.
To help occupants open windows when
conditions are favourable, and thereby
engage with the building, a green light/
red light system was developed.
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E CO L I B R I U M • D E C E M B E R 2 0 1 3
These “traffic lights” are dotted around
all areas of the workspace, with a
green light shown when conditions are
favourable for windows to be opened,
and a red light indicating to occupants
that windows should be closed.
Its unusual shape, which pays homage to
the nearby Rangitoto volcano, required
the skills of a local boat builder to
construct. Made from fibreglass, the
funnel was delivered to the site by barge
along the waterfront.
Arup’s early work also influenced the
architectural design. This is evident in
the building form, which allows natural
ventilation in through floor-plate depths
informed by CFD modelling, and the
inclusion of the atrium to act as the reliefair path.
Clohessy says the funnel’s form was
derived from meshing a surface between
the clear openings at the top and bottom
provided by Arup. These required 19 sq
m of open area in the form of slots for
return air reticulation into the adjacent
plant room.
BVN Donovan Hill’s Clohessy says
the staggered form of the atrium in
the western building was designed to
allow northern sunlight directly into
the level three internal café at various
times of the day.
“The various clear-throat dimensions
required by Arup along this path
influenced the shape of the atria and
funnel,” Clohessy says, “while the
location and routes of major ducts and
services were a result of a very iterative
design process.”
“The conventional atrium of the eastern
building maximises the opportunity for
daylight penetration from the glazed roof
to the louvre cube above, and views up to
the sky from the ASB branch at the base
of the atrium,” he says.
The funnel draws internal air into the
louvred “cube” at the top of the building.
THE FUNNEL
When weather conditions are favourable,
the air rising through the building funnel
makes its way out of the building via the
cube, which incorporates a motorised
damper and louvre arrangement.
The atria follow the fresh-air pathway
through the building up to its most
prominent feature: a fibreglass funnel.
The cube was designed by Arup using
CFD modelling, taking into account the
local prevailing winds.
According to Baidjurak, these winds
are harnessed to generate a negative
pressure at the crown of the funnel. This
is achieved by closing the two windward
sides and opening the two leeward sides
in response to wind speed and direction.
This method was seen as providing an
excellent level of IEQ by flushing the space of
contaminants. The method takes advantage
of natural buoyancy forces that encourage
heat gains to rise from the occupied zone
and be removed via the atrium, roof plant
rooms and through the building’s funnel.
“There was robust debate at the early
stages of the design to locate these
features within the highest part of the
site planning envelope to generate the
necessary stack effect and harness the
prevailing winds rather than fill this
space with potentially higher-value
offices,” says Baidjurak.
“By accepting this building form, our
clients demonstrated their appreciation
of the value of IEQ, staff health and
well-being.”
FROM THE GROUND UP
Various mechanical ventilation systems
were considered at the concept stage,
including chilled beams, variable air
volume, in-slab heating and cooling,
and other combinations. However, a
displacement system boasting high IEQ
performance was ultimately deemed most
suitable to operate in mixed mode with
openable windows.
Both the client and architect welcomed
this selection given that displacement air
delivery ensures occupants receive the
freshest air.
In lieu of a traditional raised-floor
delivery ASB elected to adopt a “fixed
bin” approach on the basis that the fit-out
was designed for the long term.
“Once the mechanical strategy was
agreed, the design team worked through
the potential locations of displacement
bins within the workplace fit-out and
established the associated clear zones
around each one,” says Clohessy.
FE ATURE
The team developed a mix of bespoke
joinery, balustrades and walls with
integrated displacement outlets as well
as a series of proprietary free-standing
“bins”.
Two types of workspaces
are provided: the
public space known as
“boathouses” and free
working spaces known
’
as “neighbourhoods
These were located in the perimeter zone
as well as central zone areas. For more
open-plan areas and circulation spaces,
Arup worked closely with the architects
to design custom-made displacement
outlets from “first principles” calculations
to determine the plate perforations
required.
FE ATURE
The building is designed to maximise access to daylight, views and fresh air.
Baidjurak says taking into account the
comfort supplied from the “near” zones
affected the decisions made around
locating other displacement outlets,
and ultimately influenced where office
furniture and seating were located.
To help occupants open
windows when conditions
are favourable . . . a green
light/red light system
’
was developed
“We maintained separation from
occupants of 1,200mm for the near
zones based on the advice from the
displacement outlet supplier, our
modelling and consideration that the
relatively high temperature supply air
would be delivered on a variable-volume
control strategy,” he says.
This exercise was highly iterative and
required a high level of coordination.
Every time an element in the fit-out
moved, it potentially affected the bin
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E CO L I B R I U M • D E C E M B E R 2 0 1 3
location and the mechanical ducts
feeding that bin.
“It would be fair to say that this was
one of the more challenging and difficult
facets of the design process to resolve,
and equally one of the most rewarding
for the team,” Clohessy says.
THE HVAC KIT
Serving the displacement system is a
central HVAC plant consisting of three
scroll-type air-cooled chillers running
on zero-ODP refrigerant, to provide
chilled water to the main air-handling
units (AHU) and fan-coil units (FCU)
on each floor. Three units were selected
to provide redundancy, with a total
capacity of 1,700kW.
Two high-efficiency condensing gas-fired
hot water heaters, with a capacity of
1,400kW, provide heating hot water
to the main AHUs.
The custom-made AHUs feature
high-efficiency plug fans and a
return-air bypass section to allow
for dehumidification cycles given
the relatively high humidity of the
outdoor air.
“The AHUs have been designed to
minimise pressure drop and to save
fan energy given the units will run
for a significant portion of the year in
mechanical ventilation mode,” says
Baidjurak.
Based on psychrometric analysis,
Arup found that by taking advantage
of the economy cycle and using bypass
reheat when required, the project’s IEQ
requirements would be satisfied for most
of the outdoor conditions through the
year, without active cooling or heating.
Chilled and hot water pumps are
configured in a primary/secondary
arrangement with low-pressure drop
headers and a magnetic-flow meter.
Two-port control valves are installed
in the field, with three-port valves
at the ends of main runs.
“While the equipment has been selected
with high efficiency in mind, our main
aim was to minimise air-side pressure
drop and hence fan energy, given the
IEQ conditions could be satisfied with
a combination of mechanical ventilation
and openable windows for most
of the year,” says Baidjurak.
The distinctive funnel draws
internal air up, and pays homage
to the nearby Rangitoto volcano.
The central plant also includes a range of
fans for relief air, smoke extraction and
general ventilation to tenant areas.
under exposed services, and cable
trays feed the workstations with power
and communications from below.
Given the building’s seaside location,
consideration was also given to corrosion
risk. It became a key influence on the
selection of materials, air filtration and
positive pressurisation of the plant rooms
to maximise longevity of the equipment.
Baidjurak says it’s a common
misconception that exposed services
leads to an easier design and fit-out.
Our ESD and mechanical
LEFT EXPOSED
engineers took a ‘first
According to Clohessy, in designing the
workplace as a fully integrated fit-out,
the client’s choice to have services left
exposed in the ceiling zone tells the story
of how the building works.
principles’ approach
“All services needed to be ‘joined at the
hip’ to create a considered reticulation of
services,” he says.
inform the IEQ solution
“Mechanical ducting is physically the
biggest element within the services zone,
so the design and coordination was
critical to the aesthetics, and ultimately
the success of the entire services lay-out.”
From a practical point of view, the fully
exposed services allow the mechanical
services design to take advantage of the
thermal mass of the exposed slab. The
myriad of undulating services also work
well acoustically, scrambling the noise
generated by the open-plan office lay-out.
The spaces created by the exposed
services also provide opportunity from
an architectural design point of view. For
instance, the freestanding pods that make
up meeting rooms were able to slot in
and studied the local
environment in order to
’
“The design of an exposed services
scheme that meets the engineering
performance and project budget – as well
as the aesthetic objective – is a challenge
not to be underestimated,” he says.
BVN Donovan Hill’s collaboration with
Auckland architects Jasmax was also key
in realising the meticulous attention to
detail achieved throughout the project’s
design and construction. Various reviews
of samples, mock-ups and construction
methodologies played a role here.
“This project illustrates a premium
level of exposed services design that
I believe would have very few peers in
the Australasian region and abroad in
terms of design and installation quality,”
says Baidjurak.
Meticulous attention to
detail has been achieved
Fthroughout
E A T Uthe
R project.
E
D E C E M B E R 2 0 1 3 • E CO L I B R I U M
23
FE ATURE
LESSONS FROM THE CONSULTANT
1. Revit 3D modelling requires an open discussion at the outset of the project to agree on the level of detail
necessary from the building services disciplines. Modelling of exposed services and coordinating all final
services penetrations is a significant undertaking, which requires a substantial and collaborative team effort from all designers.
Our experience with Revit 3D on this project has contributed to the development of level of detail (LOD)
definitions and use of a BIM execution plan on all Arup projects, which is agreed with project stakeholders prior to pushing ahead with the modelling.
2. Exposed services must be agreed upon during concept stage, and all the major principles resolved during
design development, as the strategy will likely influence all services reticulation on-floor, and potentially the riser shaft massing arrangement.
3. The level of detailed design documentation for finishes, fixings and set-out should be given ample time in the design program. Accurate, elemental budget pricing should be completed by the project team, as the strategy can add a hefty premium to traditional services reticulation.
4. Construction stage collaboration; having our local building services sub-consultants Babbage with a significant site presence helped tremendously with communication and resolution of RFIs and reviews of installation quality against design intent. Our team made many trips to site for critical issues, witnessing
testing and to fast-track a number of client design changes during the construction stage.
FE ATURE
“I have seen many other projects where
the ceilings were simply removed from a
traditional services reticulation scheme
and, in my opinion these are far less
visually appealing.”
Of course, exposing services also throws
up design challenges.
A major one that required significant
collaboration and a clever approach was
the erection of 1,500mm-diameter mainsupply air risers in the atrium. These had
to appear self-supporting.
Because the design intent was for there to
be no visible secondary structure bracing
them, the mechanical services team,
the architects, structural engineers and
acoustic consultant worked together to
develop a concealed means of supporting
these major services elements.
“Our solution was to create a hoopand-strap system within the riser shaft,
suspended from a central column that
hung from the roof structure,” says
Baidjurak.
Engineering for indoor air quality puts staff health at the forefront of the multi-level building.
Lateral support was provided by
concealing structural elements within the
riser take-offs, which were then fixed to
the structure under each floor plate.
“The designers and contractor persevered
as a project team to refine the design
for installation, which ended up being
prefabricated in sections off-site for the
FE ATURE
Hidden support for exposed services required some problem solving.
large ductwork and takeoff pieces,
and the internal hoop-and-strap system
installed from a scaffold top-down with
a series of pulleys.”
REALISING
THE ASPIRATION
Buildings of this complexity can only
be realised through close collaboration
between engineer and the architect.
Anything is possible with the right
“Complex buildings and innovation
take time and a dedicated team to resolve.
ASB North Wharf was completed
in June 2013. ❚
The professionals
Major tenant: ASB Bank
Acoustics: Marshall Day
Mechanical services
contractor: Aquaheat (Hastie)
Architect (Base build): BVN Donovan Hill in association with Jasmax
“Overall, the benefits come to all parties,
as we now understand each other’s
method of working better than on our
last project,” he says. “This knowledge
can be leveraged for even better
outcomes in our future work together.”
E CO L I B R I U M • D E C E M B E R 2 0 1 3
attitude.”
PROJECT AT A GLANCE
Although the usual negotiations over
available space took place, Baidjurak says
the benefits of the collaborative approach
to design are evident in the quality of the
solutions, which could only come about
by understanding each stakeholder’s
needs and drivers.
Clohessy says this particular design
necessitated that the entire design team
shared the passion and aspiration of the
client, and in turn the resultant design.
26
“Everyone at the table had to be fully
engaged in the process and the dream,”
Clohessy says.
Project manager: Octa and Associates
Architect (Workplace): BVN Donovan Hill
Structural engineer: Buller George Turkington
Building contractor: Fletcher Construction Company
The equipment
Building services engineers: Arup, in collaboration with Babbage
AHUs: AirPack
Client: Kiwi Income Property Trust
ESD: Arup
ICA: HVAC Solutions
Fire engineering: Holmes Fire and Safety
Air-cooled chillers: York
BMCS: Schneider electric
Condensing boilers: De Dietrich
Displacement outlets: Trox
Grilles: Holyoake
Pumps: Wilo