Tensile was contracted to design, supply and install new ‘green screens’ at Taronga Zoo’s Wildlife Retreat accommodation buildings in Sydney, a project which demonstrates how green façades can also be utilised as fall protection barriers.
The luxury accommodation, which was designed by Cox Architecture and built by Taylor Constructions, comprises 62 rooms within five multi-storey buildings or ‘pods’, as well as an entry pavilion, restaurant, and external terrace.
Each of the pods – which are connected by elevated walkways overlooking central animal sanctuaries – has its own green barrier, made from vertical wire cables that support climbing plants at each level.
The green barriers overall create privacy, shading, and a dappled-light effect for the guests, while still providing views of Sydney Harbour.
Various studies have shown that simply being around plants can help improve concentration, memory retention, mood and work performance, as well as being proven to increase psychological wellbeing and recovery time for both physical and mental conditions.
This is especially important in urban environments where parks and gardens are infrequent due to space being at a premium.
To enable greenery in often dense urban spaces, green façades can be installed on building walls to beautify, cool, and provide shade. For longevity, these systems generally consist of a support structure for climbing plants and tendrils usually made of metal, which offer superior strength and wind resistance.
Green façades are becoming increasingly prevalent in Australia, with Tensile seeing an increase of 300 per cent in the number of façades installed from 2010.
Prior to installation at the Wildlife Retreat, Tensile partnered with landscape architect Turf Design to create a prototype onsite that showed how the finished design would work.
The prototype demonstrated that the vertical wires (four-millimetre Jakob stainless steel wire rope) would provide consistency and stability, despite the level of expected dynamic movement across the façades.
A major priority for the client was to achieve dense plant growth across the façades relatively quickly, which would typically require cross cables to be installed.
However, Tensile together with Turf came up with a better solution, installing the cables in a continuous vertical pattern across the building façades, balconies and walkways, which supported native plants at every level while also providing fall protection.
Green façades or walls can mitigate the effects of air pollution and temperature in urban environments, with research showing that vertical gardens can reduce local temperatures by several degrees.
According to the Australian government’s guide to environmentally sustainable homes, green infrastructure contributes to cleaner air by filtering out up to 95 per cent of the pollutants generated by vehicles and industry.
As well as improving comfort and air quality, the shading and cooling effect of a façade can improve HVAC efficiency and reduce the need for mechanical cooling, reducing costs and carbon emissions in the process.
Modelling done for the South Australian Government on living wall systems showed it was possible to measure potential changes in average heat gain from a façade prior to its installation.
This was achieved by calculating the wall’s envelope thermal transfer value (ETTV) which consists of three elements – heat conduction and solar gain through the windows, and heat conduction through the wall.
After calculating a wall’s ETTV, it is tested on various living wall scenarios against a control.
It was found that changes in ETTV for a 20-storey wall with dense plant coverage in a tropical climate could be as high as 40 per cent.
