FLOATING ROOF TOP GARDEN

Skyparks - Westfield Bondi Juntion

Through the NSW Greening the City Innovation program Waverley Council in partnership with UNSW received state funding to implement and research cost-effective integration of vegetation onto exposed urban space, and to provide cooling and associated resilience co-benefits.

Council partnered with Scentre Group and Landscape Architect Alex Georgouras from Common Grounds to install a Roof Top garden to better understand benefits and barriers for providing scalable and transferable options for transforming car parks, terraces and other urban spaces into thriving gardens for social interaction.

Trialing native vegetation and topography in garden trays

 

From completion of the design process, the next step was working out the installation process.  To reach the top of the Westfield Car park roof we were limited by a 2m height restriction and no possible way to bring material on site via crane.  Every component including soil, plants, decking, furniture and other material had to be brought up individually via trailer. We had to logistically transfer from truck to trailer and this took 20 round trips to get all material on site.

The roof top was pre painted before installation began.

Furniture was sourced from Street Furniture Australia.

We used the levelling feet of the Decking Trays and Tree Planters to create flat surfaces.  We plumbed in water refill to top up the water reservoirs in the Tree Planters and Garden and Turf Trays, setting them on a timer.  This greatly reduced maintenance requirements.  Installation took three days.

Native vegetation growth after one year in the Garden Tray

Design cross section of roof top garden

 

Alex is passionate about protecting remnant vegetation from the Eastern Suburbs of Sydney.  We wanted to test the potential of our Garden Trays to be able to successfully grow these natives in a hostile environment. We also wanted to mimic the soil profile and topography.  We undertook a trial build and 3 month grow out to determine the plant needs and what mulch worked best to prevent water loss.

From this research we were able to determine soil type, profile and watering requirements.

The next stage was working with Alex to bring his vision into shop drawings.  A major design feature was the varying heights of the Tree Planters and that each side of each box was a different powder coated colour. Alex also wanted a powder coated metallic edging for the perimeters of the garden trays.

We worked with Metal Benz to design all metal requirements for the project.

Installed garden March 2022

The roof top garden was opened in March 2022.  The roof top is very exposed to strong winds and sun as well ambient heat coming onto the site from the surrounding car spots.  However plant survival rates were well above expectation and the remnant vegetation is flourishing.

Native vegetation in Tree Planters after one year