Living architecture is part of a broader notion of green infrastructure that also encompasses water sensitive urban design, integrated water cycle management, green streets, urban food, and the urban forest.
When combined, these elements can reduce the negative impacts of urbanisation to make our cities more liveable.
The following is a description of the typologies and elements that comprise living architecture:
A green roof can be a space that people occupy and enjoy with generous planters that support trees and large shrubs. These are known as intensive roof gardens and they have relatively heavier loads and a higher cost than other types. Their deeper soil, however, provides a buffer for water supply if the irrigation fails, meaning that vegetation will survive periods on hot days without irrigation.
Depending on the project requirements, intensive roof gardens can be designed having different degrees of intensity and range of vegetation types.
Alternatively, a green roof can be a very shallow garden and still support lush and resilient plantings. These green roofs can be relatively inexpensive, are lightweight, and have lower water demand for irrigation.
However the thinner the profile, the greater the risk of the plants dying if the irrigation fails.
It is also possible to have a combination of lighter and more cost-effective extensive green roofs within occupiable roof gardens.
Green walls and facades
There are two main types of vertical garden systems, green walls and green facades, which can be further broken into different categories.
A green wall can be either a modular or containerised system holding planting media or a fabric-based growing system.
The fabric-based green wall systems are entirely reliant on irrigation and as a result, any failure in this area will result in rapid plant death.
A modular green wall uses planting media to support plant growth and as a result can withstand periods of drying before the plants die. These are important considerations when designing for resilience.
In contrast, a green facade involves plants grown out from a building wall or glazed area, either climbing up or hanging down.
Typically, green facades feature climbing plants utilising specialised cabling/trellis support structures which are suspended forward from the wall or glazing. Plants can be grown in-ground and reach up to four to six metres, or they can be grown in containerised systems which can be at considerable height.
Green facades have the advantage of providing plant coverage across large areas at low cost. They are also relatively resilient in terms of water demand.
A green facade can also be a form of exaggerated balcony greening where significant planting, including trees, can be provided at height.
There are many possibilities to combine and hybridise these elements integrating them with innovative architectural design in meeting the specific project requirements.
The challenges of establishing living architecture in Australia
Green roofs, walls, and facades are more common in other countries than in Australia.
In the northern hemisphere, the climate is generally cooler and they have fewer extremely hot days with rainfall distributed relatively evenly across the year.
Living architecture is particularly prevalent in Singapore. This is not only because of their tropical climate with constant temperatures and rainfall, but also due to the direct support of their government, which actively encourages and even mandates for green roofs, walls, and facades.
It is a considerably different challenge getting living architecture to successfully establish itself and remain vigorous on buildings in Australian cities.
Our climate has frequent hot days and extended periods of little or no rainfall. It is essential that these elements are designed with climate in mind.
Key considerations include plant species selection as well as careful design of the substrates and horticultural systems that support them. Irrigation is a critical consideration in Australian cities.
Perhaps due to our challenging climate, the perception of green roofs, walls and facades is that they generally won’t work; people feel it is just too hot, too windy, and the plants will die. In addition, the development industry generally perceives them as being too costly, needing too much water, and involving too much maintenance. The underlying perception is that the costs of these things outweigh the benefits.
Living architecture solutions
Over a number of years, we have been developing our technical understanding of living architecture here in Australia.
This progress in our design thinking was in no small way accelerated through the Victorian Desalination Project, which involved research and development to ensure a 2.6-hectare extensive green roof could be constructed and operated successfully in the absence of an Australian Design Standard.
The One Central Park project has also allowed us to gain a thorough understanding of the design challenges, technical difficulties and operational and maintenance implications associated with large scale vertical greening.
Other notable green roof and green facade projects include:
- A green roof on a fire shelter and multi-use building in the Yarra Valley
- A green facade to a multi-level car park in a luxury apartment building on City Road Southbank.
- A green facade to a new council office building in Greensborough
These projects have utilised design solutions that address the challenges faced in Australia that enable living architecture to thrive.
Structural support systems
Living architecture has load bearing requirements in terms not only of dead and live loads but also wind. Both the loads that need to be taken up for the support structures themselves, as well as the loads the support structures impose on the building frame, must be known.
It is important to work with the architects and rest of the design team to integrate the living systems with the building envelope
The visual appearance of the support structures play just as an important roles as the plants themselves. Living architecture needs to be good architecture.
Horticultural Support Systems
Working with leading industry consultants and suppliers helps to ensure the planting media and species selections provide the plants with the tolerances that ensure success.
Projects must demonstrate that their performance, in terms of design against wind action, light penetration and air flow, meets requirements.