We completed this alterations and additions project to an existing house in Glen Iris a few years ago. The existing house already had good orientation to the living spaces. We designed a new building containing the sleeping zones with its long orientation to the west. Conscious of having the major orientation to the west we designed a green screen across the face of this wall. A simple galvanized steel and timber structure was fixed to this west facing brick wall to allow greenery to grow up the wall and protect the building from solar radiation and heat penetration in summer. Green walls don't need to be complex structures that are cost prohibitive. A simple structure can provide the framework for plant growth that is thermally effective and also visually pleasing.
The main sustainable advantage of building a green wall is that it will provide insulation and shading to that wall in summer. In this instance using a green wall along a west facing wall provided some insulation against the low hot western sun in summer. The insulation is provided not only by the physical barrier of the plants, but also by the air gap between the plants and the building. Therefore holding the plants off the building is preferred. We fixed a sustainably sourced Australian species cypress battens to the wall. A galvanised steel mesh was then fixed the battens. Cypress is a class 1 durability timber (above ground) so it is a good timber to use externally as it will have a longer lifespan than just ordinary hardwoods. We typically specify sustainably sourced Australian cypress for some inground and above ground use.
By strategically locating a green wall on a building, it can be used to help insulate and shade a building and act to reduce the heat load on a building. This is a passive sustainable design strategy.