The Australian PlantBank is a research facility of the Royal Botanic Gardens and Domain Trust, located at the Australian Botanic Garden in Mount Annan, south western Sydney. Housing the Trust’s seed bank and research laboratories, it specialises in native plant conservation and will eventually conserve 100 per cent of New South Wales flora.

With such a strong purpose – the facility is positioned globally as a symbol of preservation of the natural cycle of a seed, from germination to the propagation of forests – the brief naturally warranted a building that would not only offer the appropriate facilities, but also a design that is easy to understand, revealing its research through public interpretation and exhibition activities.

The site of the building is the first call out to the nature of the institution. Located beside the endangered Cumberland Plain Woodland and bookended to the south by a plant nursery, the building introduces a dialogue between the natural systems of the woodland and the cultivated, controlled nursery.

This transformational character of the intellectual and practical functions of the organisation underpins its design. For instance, journey from the visitor car park to the natural setting of the building stresses the pre-eminence of the landscape, with visitors and staff needing to ascend six metres from the road level before they can enter through the front door located opposite the woodland. This pathway is framed by 4.5 metre toughened curved glass panels.

According to BVN Donovan Hill’s (now just BVN) national director, James Grose, the incision in earth to enable this experience is “further evidence of the nature metaphor – the moving between shadow and light, the entry to a cave or simply the idea of moving from the vastness of the Australian landscape into the intimacy of the forest.”

Similarly, the façade of the building works to reinforce the idea of an organisation that is directly involved with, and a part of its landscape. Featuring a series of mirrored panels interspersed between large windows shaded behind perforated metal screens – an element builder Hansen Yuncken says is the first construction of its kind in Australia – the profile of the building reflects the site so it appears to be immersed in it. As such, the line between the building and nature is purposefully blurred.

The merging of built and natural forms is also evident in the design, with the lichen gardens using remnant sandstone blocks rescued from demolished buildings to host exotic plant colonies. The architects refer to this as the “symbolic returning of the once shaped urban sandstone back into its natural composure”.

Colour controlled concrete walls with blow holes and landscape walls that splay and change direction in a series of triangulations add to the three dimensional illusions of the building. Operable louvres enabling mixed mode ventilation protect certain windows, and are sealed by stainless steel bushfire mesh.

The metaphorical call outs do not stop in the external realm. Inside, finishes have been chosen to articulate the different characters of the open plan workplace spanning east to west. From the entry through to the lobby, visitors have visual access to researchers working in labs. They are also able to view the incubators, cold storage facilities, and Seed Vault.

“The Seed Vault is the conceptual focus of the research, being the repository of seeds,” said Grose.

“The visitor heart of the building is the narrow lobby form at the junction of the research, workplace and information zones of the building. From the lobby the visitor can see all the internal functions of PlantBank and because of the thinness of the plan emphasising the woodland, the backdrop is surrounding nature.

“The conundrum is that the interior functioning of the building is only accessible during working hours. The architectural strategy for interpretation has therefore taken a wider view of the building in the setting and landscape of the Garden.”

Other facilities include a multipurpose room used for seminars and events, meeting rooms and lecture theatres, and an underground thermal labyrinth.

“A thermal labyrinth has been installed under the east wing which reduces the HVAC load and extends natural ventilation, particularly during summer when fresh air pre-cooled overnight circulates and forces out warm air,” BVN explains.

“The system is designed to reduce the peaks and throughs of extreme ambient weather by capturing either the heat of the day or the cool of the night retaining it in the surrounding concrete, earth and rock beds of the constructed labyrinth.”

Passive shading is furthermore provided to all sun shading surfaces, while the concrete floor of the public areas ensures the effect of winter sun is harnessed. Materials with low combustibility have been specified to enable bushfire protection, and water harvesting is employed throughout.

Well and truly equipped to fulfil its purpose of collecting, storing and researching on a wide variety of plant species, the Australian PlantBank is designed to be ‘of the landscape’ rather than ‘on the landscape’ – an ethos manifested in its basic form, as well as glimpsed through the sustainable and evocative materials used.

The project was shortlisted for the 2014 AIA National Architecture Awards, and is in the running for the Public Architecture and Sustainable Architecture awards.

Photography by John Gollings.