Botanical enigma: The Calyx

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The Calyx forms a protective layer that unfolds to display a precious botanical interior.

The Calyx forms a protective layer that unfolds to display a precious botanical interior. Image: John Gollings

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Rather than a typical building, the Calyx can be considered as an assembly of “suggestively delineated and light glassy volumes.”

Rather than a typical building, the Calyx can be considered as an assembly of “suggestively delineated and light glassy volumes.” Image: John Gollings

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The structure’s material lightness invites the background to become foreground and demonstrates a respect for the botanical setting.

The structure’s material lightness invites the background to become foreground and demonstrates a respect for the botanical setting. Image: John Gollings

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The design is most powerful in its capacity to continually shift perspectives between foreground and background, building and landscape.

The design is most powerful in its capacity to continually shift perspectives between foreground and background, building and landscape. Image: John Gollings

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The existing Arc Glasshouse by Ken Woolley, finished in 1987, has been gently upgraded with new glazing and a polish.

The existing Arc Glasshouse by Ken Woolley, finished in 1987, has been gently upgraded with new glazing and a polish. Image: John Gollings

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Inside, the Arc Glasshouse features the intricate organic geometries of other- worldly plants.

Inside, the Arc Glasshouse features the intricate organic geometries of other- worldly plants. Image: John Gollings

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As you approach the structure, the “fragile and light space” in the interior of the volume materializes within a nest of light and shade.

As you approach the structure, the “fragile and light space” in the interior of the volume materializes within a nest of light and shade. Image: John Gollings

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Calyx site plan.

Calyx site plan.

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Calyx floor plan and section.

Calyx floor plan and section.

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The latest addition to the Royal Botanic Garden Sydney, by PTW Architects with landscape architecture by McGregor Coxall, presents a striking geometric volume that is a protective layer and a lens that frames cinematic moments.

Calyx: “The sepals of a flower, typically forming a whorl that encloses the petals and forms a protective layer around a flower in bud.”

Approaching the Calyx, the newest addition to the Royal Botanic Garden Sydney and a prominent feature of its two hundredth birthday celebrations last year, I’m reminded of the experience of approaching the crematorium at the Woodland Cemetery in Stockholm by Gunnar Asplund and Sigurd Lewerentz from 1915. A long path rises slowly off axis and passes a lawn cut from the dominating green surrounds. There is an overall feeling of informal and easy ceremony that belies an extraordinary sense of careful design at work in the positioning and siting of the elements of the setting, while avoiding the heavy-handedness of a formal axial approach.

At the top of the rise (from the formal harbour side), anchoring the Sydney version of this scene in clear white against botanical green, the tracery of the Calyx announces itself first through colour. With detail still obscured by distance, the white sharpness of the steel elements describes the outline of a rotunda through the mass of the radially arrayed columns. Rising from the circumference of the circular plan, then bending inward to the horizontal, the columns create an internal colonnade as much as a formal geometric volume in white-lined precision against the dark organic backdrop, with both figure and field benefiting from the visual contrast.

The design is most powerful in its capacity to continually shift perspectives between foreground and background, building and landscape. Image:  John Gollings

As you move closer, the whiteness turns to a crowning of sharp verticals inscribed within the volume as the columns visually articulate themselves as individual elements. The effect is of the fragile and light space in the interior of the volume materializing within a nest of light and shade, before the perspective shifts for a third time as you close in on the structure. At this point the enigmatic space dematerializes altogether, revealing the lightness of the steel columns, which only suggest solidity – outlining the voids between lines where the greenery lies.

The existing Arc Glasshouse by Ken Woolley, finished in 1987, has been gently upgraded with new glazing and a polish. Image:  John Gollings

The overall presentation of the Calyx, designed by PTW Architects with landscape architecture by McGregor Coxall and opened last year in Sydney’s beautiful Royal Botanic Garden, is elegant and enigmatic. The material lightness of the structure invites the background to become foreground in this hallowed Sydney place and demonstrates a clear respect for the botanical setting, acknowledging and framing the botany and the flowing weight of organic green that surrounds the structure. In this context, the Calyx reverses the traditional roles of stable stone set against chaotic nature, and is most powerful in its capacity to continually shift perspectives between foreground and background, building and landscape. Only suggesting enclosure where there is none, the structure nevertheless rewards the patient view through the creation of a visually unstable depth of field elaborated by a combination of geometry, motion and lightness.

The Calyx sits somewhere between the fascination with pavilions of the moment and the history of the glasshouses of the Victorian era. It is too constrained and much too modest in its formal ambitions to be considered in the lineage of the spectacular pavilion parades that erupt around the likes of the London Serpentine every summer. Instead, the Calyx defers to a different history, one of Crystal Palaces and the blossoming of Victorian-era science, when (botanical) discoveries were being carefully catalogued in a newly discovered world. In this regard it is best not to consider the Calyx as a building at all, but rather as an assembly of suggestively delineated and light glassy volumes. Each of the three nested elements that make the assemblage cleverly activates a different scale of view, from the scale of the gardens revealed against the backdrop of Sydney’s Macquarie Street highrises to the intricate organic geometries of the unique and other-worldly individual plants exhibited inside.

Inside, the Arc Glasshouse features the intricate organic geometries of other- worldly plants. Image:  John Gollings

The existing Arc Glasshouse by Ken Woolley, finished in 1987, has been gently upgraded in the process, with new glazing and a polish and an overall respect that is maintained throughout the Calyx assembly. Woolley’s glasshouse provides the motivating circular geometry for the project, which completes the arc in the round through the white steel colonnade on its unpretentious low circular stone dais, as if to bring Woolley’s gesture to a comfortable rest in its setting. The effect of the old and new sitting together at the top of the gardens is light and clever, respectful and generally managed well, with a careful out-folding of the elements through the geometry to create the new forecourt (colonnade) and serviced foyer additions to the original glasshouse. The modest curved foyer – the only enclosed and programmable new space created in the project – sits between the existing arc and the new white circular colonnade. In this space, created between the formal new expression of the project and its older stainless steel and glass context, the services, shop, ticket area and so on are flexibly arranged so as to accommodate various exhibition configurations along the primary circular promenade of the building.

The circular array of the colonnade naturally completes the focal point promised by Woolley thirty years ago, which is staged as a small island of green surrounded by a moat. Predictably but not overly forcefully, a moment of attention is created within the structure in which all the mechanics of the geometries old and new coherently locate us within the suggested enclosure. On my visit, this stage was populated by a troupe of topiary spider monkeys eating cacao beans that linked to the theme of the exhibition: chocolate. The kitsch arrangement in this enigmatic setting was unfortunately the one jarring moment where the design of the exhibition layer was conspicuously out of sync with the architecture and the landscape.

As you approach the structure, the “fragile and light space” in the interior of the volume materializes within a nest of light and shade. Image:  John Gollings

As you walk around the rotunda and look back to the botanical gardens, the easy formality first noticed in the approach to the project is reinforced through the reverse perspective. The slight elevation of the stone platform from the lawn leading up to the Calyx is more noticeable looking back towards the harbour and creates a separation between the architecture as a viewing apparatus and the flow of the grounds around the gardens to the visual horizon.

From the interior of the rotunda, a strong cinematic impression is created. The view of the garden is sliced into discrete filmic moments, frame by frame by frame, through the rhythm and spacing of the columns as you pass by. This acts like an early movie camera to animate the gardens while also mediatizing the scene in a way that has a surprising effect given the naturalized respect of the rest of the project. In this sense the Calyx is a form of camera for the garden as a whole, a visual framing apparatus that avoids the stereotypical single-paned expanse of a modern view as much as it resists the stability of a modern architectural object rendered in light through its siting and structural lightness. Rather, the visual experience is made far more complex through the decision to create a dynamic re-presentation of the gardens in an experience akin to stop-motion animation, from within a perpetually dematerializing volume, which is the most surprising and delightful aspect of the project.

The Calyx lives up to its definition, forming a protective layer that unfolds to display a precious botanical interior. It is an intelligent structure that operates through vision and motion to shift attention from itself onto both the contents that it protects and the gardens it was constructed to celebrate.


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