Cairns Botanic Gardens Visitor Centre
- Principles of passive design for the tropics are in play
- Innovative tropical architecture encouraging deep shade, generous air movement, environmental efficiency, material strength and durability
Location: Cairns, QLD, Australia
Year completed: 2011
Cairns Regional Council sought a challenging new tropical architecture that could act as an attractor to the Botanical Gardens/Tanks Arts Centre precinct. The building was to be long, low and blend seamlessly with the surrounding environment (ideally invisible). The architect proposed a design which could reflect the gardens as camouflage for the building with a visual effect similar to the suit as worn by the alien hunter in the original 1987 Predator film. The new building was sited to straddle and activate the pedestrian promenade linking the gardens and arts centre, acting as an open and flexible conduit into the interpretive and performative spaces. It is a new, iconic gateway into the precinct, representing both “a democratic public space under-cover” and a new tropical architecture to assist Cairns in its mission to be seen as a progressive city of national and global significance.
Winner of the Architects Institute of Australia (AIA) 2012 Far North Queensland Awards – Building of the Year.
National Commercial Construction ($5 million to $10 million) National MBA 2012.
PLANNING AND MANAGEMENT
The project team had a collective desire to develop a world-class environmentally sensitive design (ESD), flexible office and mixed use public facility which wasn’t reliant on complex technological solutions or costly maintenance. The team collaborated closely with council’s public artist to incorporate art glass within the glazed promenade facades.
The client engaged in the choice of costed design strategies for the planning and form. There were significant mutual benefits such as the non-briefed inclusion of the informal amphitheatre as an alternative to excessively high retaining systems. The project was delivered on budget.
The site is situated in the Edge Hill suburb of Cairns. It is part of a cultural entertainment precinct with performance spaces and adjoins the Cairns Botanical Gardens. The functional brief was very tight for the allotted site and constrained by existing paths, roads, easements, mature trees and a gradient that made the delivery of universal access particularly challenging.
The architect set-out to design a ‘green’ building which could represent a paradigm shift for Cairns, moving away from the conventional building vernaculars toward new and progressive solutions that can be applied anywhere in a tropical latitude. There was a collective desire to attract both national and international attention, which would also aid in creating new opportunities and connections to existing facilities, communities and groups.
Principles of passive design for the tropics are in play. The buildings are positioned with the long axis elevations facing north and south. The thin plan configuration encourages maximum use of passive cross-ventilation. Heavily insulated roof overhangs to both north and south protect the thermal mass of the concrete blocks ensuring they do not gain daytime heat. Any night time cool air is stored and effectively released into the building during the following day due to the thermal lag effect. The thin plans running east-west reduces morning and afternoon sun exposure to these walls.
In addition, the visitor’s wing includes glass stacking doors which fold up completely to allow maximum airflow and open the facility directly onto the gardens.
The northern block contains the café terrace and opens to the major interpretation display and information space. The southern block is an office building for council staff with a naturally ventilated corridor serving a linear sequence of cellular office spaces that all open out to the shared staff terrace on the south.
The structure is primarily steel framed with cantilevered sections forming the large overhangs on the north and south elevations. Steel is a long lasting and recyclable building material.
The parapet cladding and promenade facades is ‘art glass’ using mirrors to reflect images of the lush gardens and blend the facility into its surroundings. This was achieved with a reflective film applied to the glass.
The lower level windows have artwork printed on the glass using a digital ceramic printing process. This complements the mirrored glass and brings an aesthetic quality both indoors and out.
Individual air conditioning control when combined with insulated internal thermal mass helps air conditioning efficiencies minimising annual energy demand. Passive design and naturally ventilated circulation corridors, high ceilings and fans also encourages mixed mode operation where by the centre operates comfortably without air-conditioning. Low energy light fittings are also installed throughout.
All glazing has a solar treatment to reduce solar and heat gain. The building generates renewable energy through a 20 kWh system. There is 104 solar panels on the roof of the structure. Excess energy is fed back into the electricity grid, providing clean energy.
WATER AND WASTE
The Visitors' Centre building has a rainwater harvesting system, and the water collected is used in the building for flushing toilets and other non-potable uses.
Purple pipes have been installed to make future use of recycled water from the Cairns Regional Council Council’s northern wastewater treatment plant which will be used for irrigation of the gardens in the future.
“The environmental principles for design in the wet tropics are simple but strict. The climate requires heavily insulated roof overhangs to both north and south, thin plans running east-west to reduce low morning and afternoon sun exposure, big openings to maximise cross-ventilation, high ceilings for fans, convective roof ventilation, cyclone-proof construction and durable materials resistant to mould and decay. Too often these principles are invoked to excuse hackneyed forms of ‘tropical architecture’.
The old resort cliché is one of swaying palms, hipped roofs, shuttered windows and chunky timbers, while jaunty assemblages of thrusting skillions, awnings and decks with clunky steel fixings forms the new norm in the north. The Visitors’ Centre demonstrates architecture of deep shade, generous air movement, environmental efficiency, material strength and durability of quite a different form.
In all respects, Charles Wright Architects has fulfilled its stated desire “to innovate and revolutionise current thinking in tropical architecture, to develop a progressive body of work intent on constant research and experimentation”.
The Visitors’ Centre demonstrates an open process of creative architects closely engaging with and informing the clients, and collaborating with good builders to give all parties the confidence to pursue new possibilities.”
Peter Skinner, Associate Professor of Architecture at the University of Queensland. From Australian Design Review, 28 March 2012 http://www.australiandesignreview.com/architecture/18473-cairns-botanic-gardens-visitors-centre
Base building architect/designer: Charles Wright, Richard Blight, Justine Wright, Katja Tsychkova
Other architect/designer: JNP Pawsey & Prowse (landscape)
Civil engineer (Site and traffic): ARUP Pty Ltd
Structural engineer: ARUP Pty Ltd
Services engineer: (mechanical electrical, hydraulic, fire): WSP Lincolne Scott Australia Pty Ltd (electrical and mechanical), CMRP Pty Ltd (hydraulic)
Project manager: Charles Wright Architects / Cairns Regional Council / Aecom
ESD consultant: Brad Pinches Consulting
Energy efficiency rating consultant: Brad Pinches Consulting
Builder: Hansen Yuncken
Photographs courtesy of Patrick Bingham Hall