Hydro Dynamics

This is an article from the Architecture Australia archives and may use outdated formatting


Left North-west elevation looking along the site’s internal street, with an interview room projecting in the foreground and the rock escarpment and wave basin in the background.

NSW government architect Peter Poulet delivers cutting-edge ecological and sun-manipulation strategies to the new suburban headquarters of the Manly Hydraulics Laboratory.

Photography by Patrick Bingham-Hall. Comment by Philip Pollard.

On a campus beside Manly Dam on Sydney’s north shore, the NSW government has built a new hydraulics laboratory to continue its 40-year tradition of research and education about marine environments.
The project brief from the NSW Department of Public Works and Services (DPWS), which operates the laboratory, required replacing some nondescript buildings facing King Street, in suburban Manly Vale, and called for a new building which was environmentally responsible and an innovative metaphor for the business.
The site is a long and rather narrow wedge, with one long side facing south-east onto King Street and the other facing north-west and falling steeply to an internal road some four metres below. The plan follows the shape of the site, but is broken into individual work and service zones. These are semi-open to each other and fully open to the access zone next to the north west façade, which provides disabled access via a continuous ramp and pedestrian stairs between the levels.
Arrival into the entry at the narrow end of the building presents visitors with a view beyond the reception desk up a series of ramps which traverse the laboratory and office spaces as the building gently steps up its site. A large painting in the foyer, dominantly in earth tones and with images apparently abstracted from the natural environment, strongly complements the building. This relationship is no mere coincidence: an explanatory note beside the work reveals that the artist is also the project architect, Peter Poulet of DPWS.
The principal environmental initiatives stem from a decision not to air condition most (90%) of the occupied spaces – the only exceptions being the computer and conference rooms. Instead of air conditioning, natural ventilation is favoured, with air drawn for summer from a labyrinth built into the rock shelf below the building and exhausted from thermal stacks/skylights in the roof.
A building management control system (BMCS) monitors temperatures in the sub-floor labyrinth, occupied areas and thermal stacks, and automatically adjusts motorised louvres in the stacks and in the sub-floor labyrinth according to pre-determined optimal scenarios. To draw cool air from the labyrinth, the windows need to be closed – otherwise air is simply drawn in the windows and exhausted through the stacks. Illuminated signs around the interior indicate when the operable windows should be opened and closed – but this relies on the occupants following the signage recommendations.
In winter, the BMCS closes the stack vents and utilises a high-efficiency natural gas system to introduce heated air via the same floor grilles as those by which the labyrinth air is introduced in summer. Adjustable external louvres on the north western façade can be set to automatically keep sun off the glass, but may be overridden to admit sun when desired.
The use of low-energy lighting coupled with high levels of daylighting (achieved with very little glare) further reduce energy demands. At the southern end of the complex, the existing large-scale wave basin research facility has been fully enclosed. A substantial array of photo-voltaic cells on its roof is designed to provide up to 10.3 kW of energy; either to the building or, when not required, back into the grid.
During the design phase, the building was modelled by the CSIRO for thermal and ventilation performance. This influenced the selection of internal materials, including concrete in-situ slab floors, which are insulated where exposed to the outside air, and the extensive use of concrete blockwork for sub-floor areas and internal service zones. Roofs are also double-insulated, with the void vented via the roof stacks. A night purge, assisted by mechanical ventilation via the sub-floor labyrinth, helps remove heat from areas of high thermal mass.
Below Main entry to the complex with water wall at left. Bottom Looking north along the driveway from the rock escarpment at the south end of the site. At right is the higher wing containing staff amenities, conference and interview rooms.


Hydro Dynamics

The building has been occupied for just over one year, and its first summer highlighted some areas where fine tuning to the ventilation system was desirable. This work is currently being completed and includes modifications to the solar vents so as to absorb greater heat and hence increase air flows in summer. Air flows within the occupied spaces have been supplemented by wall-mounted fans.
The first year of use of the building also revealed that some occupants had not been properly briefed about the performance limitations of a naturally ventilated building. On the few days (usually three a year) that temperatures exceed 35 degrees, the interior is unavoidably warm – but still cooler than the outside temperature in spite of heat loads of computers, copiers and other equipment.
Whilst it might be argued that the natural ventilation system may have benefited from more sophisticated design modelling, the underlying principles are clearly sound and, even without current refinements, performance appears to have been satisfactory. Further modifications have potential to improve this performance.
Many of the occupants move in and out of the building throughout the day as they go about their research and other activities. Typically, staff dress according to the weather – they do not have to drastically alter their attire as they would if the workspace was fully air conditioned. Occupants enjoy the opportunity to maintain a relationship with each day’s weather, and a degree of control over their physical environment which is typically denied to occupants of buildings equipped with central air conditioning systems and artificial lighting.
The quality of the different work spaces and the opportunities afforded for collaborative work appear to be quite conducive to the types of activity going on in the building. Most spaces have pleasant external aspects, and there are a number of outdoor decks and external spaces which are readily accessed from the work areas and common room. Placing the external fixed timber sun shading a minimum of 1.2m away from the glazing has created a range of intermediate interior spaces.
The detailing of these shades, with tall western red cedar blades arranged to cut out direct sunlight, also affords generous outlooks.
A reticulated pond below the building at ground level follows the line of the north west façade, and a clear glazed floor panel, level with the disabled ramps, allows glimpses of the ponds and water plants from the interior, as well as providing dynamic reflections from the moving water onto the building’s ceiling.
Peter Poulet’s painterly talents are evident in the interior colour scheme, which uses neutral colours on the perimeter elements and most work spaces, with a variety of stronger colours on the masonry internal service blocks.
When considering buildings which aim to save energy via natural ventilation, it is important to remember that there have been only a few recent Australian office/commercial/laboratory precedents for designers to reference. Even after many decades of designing air conditioned office buildings, we still too often see HVAC systems which do not perform adequately, and where shortcomings are simply masked by cranking up the chillers and burning more energy.
In contrast, the Manly Hydraulics Laboratory appears to be a comfortable and very attractive space in which to work. The complex sits appropriately in its urban context between residential buildings and the public recreational space and bushland associated with the Manly Dam.
It serves its client well, both functionally and in terms of the metaphor it suggests to the laboratory’s clients.
Phillip Pollard is the Senior Architect/Planner of Physical Planning and Estates at the University of Newcastle

Cedar vertical louvres screening the east facade of the administration zone. Above Staff amenities room and deck overlooking a garden pond which cools air entering the building.

Manly Hydraulics Laboratory, Manly Vale, NSW
Architects and consultants Government Architect’s Office, NSW Department of Public Works & Services— project architect and design architect Peter Poulet; project manager Stan Weeks; architectural team Sam Macri, Ben Hewett; environmental consultants Eric Yeo, Zig Peshos, Vicki Horan; structural & civil Hari Gohill; electrical Tony Aldridge; mechanical San Mai, Mark Hopkinson; hydraulics Mark Buckeridge; landscape Bruce Thomas; quantity surveyor Richard Wong


Hydro Dynamics

Above Site plan. Cedar sunscreens along the north-west facade of the lower wing.


Hydro Dynamics

Top Informal first floor meeting platform with stairs to service areas below. Bottom North-west facade.



Published online: 1 Jan 2000


Architecture Australia, January 2000

More archive

See all
August issue of LAA out now August issue of LAA out now

A preview of the August 2019 issue of Landscape Architecture Australia.

Houses 124. Cover project: Garden Room House by Clare Cousins Architects. Houses 124 preview

Introduction to Houses 124.

Architecture Australia September/October 2018. AA September/October 2018 preview

Local and global recognition: An introduction to the September/October 2018 issue of Architecture Australia.

The August 2018 issue of Landscape Architecture Australia. August issue of LAA out now

A preview of the August 2018 issue of Landscape Architecture Australia.

Most read

Latest on site