The Calyx – Royal Botanic Gardens

The Calyx, designed by PTW Architects, is a circular peaceful arbour pavilion situated in the Royal Botanic Gardens. The work involved construction of a new entertainment and display facility and integration to an existing ARC glasshouse which was also totally refurbished as part of the program.

About ‘The Calyx’

The Calyx’s primary use is to accommodate seasonally rotating, high impact horticultural displays located within the Arc Glasshouse, with the exhibitions changing every four to six months. An additional facility was designed to provide a space for regular hospitality events. The Calyx can be hired for weddings, corporate entertainment, cocktail parties, art, trade and cultural exhibitions. An associated foyer space has been provided with amenities to support these functions.

The project took around 2 years from concept to completion. JHA Consulting Engineers were engaged by the builder, Cockram Constructions to supply Electrical, Specialist Lighting and Level 3 services.

‘The Calyx’ pavilion, made up of curved repeating steel structures, is transformed at night by 76 colour changing up-lights. Lit from the base the intricate lighting gives the structure a vibrant and dynamic feel. A beautiful playful environment is created as the luminaires wash the architecture whilst putting on a brilliant light show.

The Calyx Royal Botanical Gardens
‘The Calyx’ pavilion, made up of curved repeating steel structures
The Calyx is transformed at night by 76 colour changing up-lights

The Challenges

Supplying level 3 services in a heritage area was one of the biggest challenges. Due to higher power requirements power to the site needed to be upgraded to a higher voltage.

A new electrical substation had to be located close to the site. To add to the problems the service road leading to the area had many heritage trees with roots that went far beneath the ground that could not be disturbed, making laying of the new high voltage cabling an issue.

JHA were engaged to liaise with Ausgrid for the design and documentation of the High Voltage substation. Ausgrid raised concerns about the trenching works which had potential to damage possible unknown aboriginal artefacts under the service road (or under Mrs Macquarie’s Chair Rd).

In the same way that the potential for Aboriginal artefacts causes issues for any design, the potential for interfering with trees (roots) causes similar issues and initiates the same type of processes.

We coordinated with Royal Botanic Garden and the archaeologist for the trenching route. It was proved to Ausgrid that the proposed route was viable and buildable.

Other challenges on the project ranged from concealing cables and lights within the structure whilst still allowing maintenance and ventilation, providing services in difficult areas (such as green walls), ensuring flexibility of services (such as providing accessible power outlets to remote spaces where it may be required), as well as the usual challenge of providing a cost-effective lighting implementation of a conceptual lighting design.

Since completion PTW Architects have won a Good Design Award for the design of ‘The Calyx’. JHA is proud to have partnered with Colbros on this iconic project to deliver a dynamic and colourful external space through our specialist lighting and electrical engineering teams.