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.
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