A glass pleated, carbon neutral pavilion fit with innovative glazing technology has been added to northern entrance to the Australian Museum in Sydney.
Designed by Neeson Murcutt and Joseph Grech Architects as a simple, open plan elongated space, ‘Crystal Hall’ is intended to “float transparently” off the museum’s sandstone northern façade and to form a gentle junction with the historical building. But don’t let this simple description fool you.
Measuring 20 metres long by eight metres wide, Crystal Hall responds directly to the Museum’s brief for an elevated, highly transparent, elegant glass pavilion for its William Street entrance, but it also functions as an experiment with glazing.
Its north facing façade, the largest of the pavilion’s exterior walls, is its draw card and is defined by a bespoke, zig-zagged crystalline screen. Extended vertically and horizontally beyond the floorplate, the screen features 24 stainless steel-framed, 8.5 metre high panels formed into 12 vertical ‘pleats’.
The stainless frames accommodate triple-low-E, double-glazed units that were specified to allow only a select amount of daylight into the museum’s entrance while reflecting short wave and infrared heat.
But it’s inside that the experimentation begins, and it comes in the form of forty-eight unique crystalline diamond-shaped, coloured glass ‘blades’ that hang from the ceiling in six different ‘soft colours’ - shades of mauve, blue, pink and yellow.
Developed for the first time by Neeson Murcutt, Joseph Grech Architects and Arup engineers, the blades are positioned internally along the northern façade, angled and pivot-hung in each pleat (four per pleat) to refract and diffuse light, manage solar glare and capture heat, allowing it to be vented up and out through the ceiling.
Each diamond-coloured ‘blade’ comprises three sheets of glass, and operable positioning within each pleat. The first sheet, prismatic glass to diffuse as much light as possible; the second, a coloured layer for glare; and, the third a frit (spotted) layer to help with shading. Sets of blades can be re-angled to deal with changing climatic conditions.
The architects expect the system will mean that the north-facing glass hall will only need natural ventilation for most of the year.
Commenting on Crystal Hall, Neeson Murcutt Director Rachel Neeson says that her team’s intention was to deliver a pavilion that provoked interest from the outside but actually functioned as a space to view out.
“Our concept was to create a new glass façade that would generate its own interest running parallel to the existing sandstone façade,” says Neeson.
“A crystalline screen that would be like a glass wall you could sit behind, rather than a glass box you go into. We then worked to fit the narrowest box possible behind this, with a narrow band between the new façade and the existing building.
“This new pavilion was then linked gently to the museum with a connecting bridge, with an existing hallway inside the museum streamlined to improve visitor flow and wayfinding.”
Crystal Hall, which houses a selection of the AM’s extensive crystal collection, was completed in less than 14 months as one of several Stage One transformation projects, others being the opening of the new 630 square metre Wild Planet gallery, three other new galleries, a public lift, a new rooftop café offering views of St Mary's Cathedral the Domain and the harbour, as well as a new AM store and upgraded atrium space.
KEY SUSTAINABILITY INITIATIVES
- Crystal Hall incorporates both passive design features with an active environmental control strategy. Passive Design features include:
- A state-of-the-art, triple-low-E, double-glazed façade selectively allows daylight in but reflects short wave and infrared heat.
- An internal screen on the northern façade comprising 48 adjustable crystalline blades are used to shade internal spaces from direct solar glare.
- A secondary internal blind system is installed as backup to the north, east and west.
- The crystalline blades also absorb solar radiation (in the same way as external shades would), which is vented through the roof.
- Light fittings are low energy.
- Materials are robust and befitting of a public institution – glass, stainless steel, steel, zinc and bluestone – with as much sourced locally as possible.
Active environmental control strategies include:
- A chilled/heated floor removes solar load as it hits the bluestone, while also providing winter heating, allowing the hall to operate in a naturally ventilated mode for 95 per cent of the year.
- An air-conditioned outdoor supply air system provides spot heating and cooling under peak conditions, or if the space is being used for a function.
- A solar photovoltaic system has been installed on the roof of the main museum to offset the hall’s energy use.
