 and strategies. This renewed planning focus has led to the Australian government—through the Council of Australian Governments (COAG) and the federal government’s Major City Unit—taking a much greater interest in the mechanisms whereby affordable and sustainable inner-city housing can be provided. However, the production of conventional apartment buildings using concrete, aluminium and steel are one-way energy-intensive processes that release large amounts of greenhouse gases into the atmosphere. One strategy to achieve more sustainable and affordable housing is to design and manufacture ‘green’ assemblies for mass customization of buildings using modular prefabricated low-carbon construction systems. The vision of ‘making buildings without making waste’ could become a reality .
Behaviour change has frequently been listed as the number one barrier to reducing consumption towards pro-environmental behaviour and a more energy and material-efficient, low-carbon future [28,29,30]. The term ‘behaviour’ can be defined as an active responsiveness to current environmental issues, believed to be pro-environmental by the person performing the response. Tackling the carbon intensity of development and urban sprawl concurrently requires finding low-carbon alternatives for urban infill development—for instance, living without car parking space on-site but within easy reach of public transport choices—and not compromising mobility and quality of life. Technology is most effective if it is embedded into a societal framework. However, residents’ motivation and commitment to aspire to sustainable living are still not well understood, for example how to best overcome barriers to low-carbon living.
2.1. Buildings Should Be Like Trees and Cities Like Forests
Besides our historical, poetic and emotional connections to wood, as a construction material it offers several important environmental benefits. It is renewable, it stores carbon that has been sequestered from carbon dioxide in the atmosphere, it can be rapidly regrown, it provides excellent opportunities for re-use and, when harvested from certified sustainable forestry and properly recycled, it can serve as a carbon-neutral source of energy or construction material.
‘Timber’ is what we call wood that has been cut for use as building material. We tend to use both, wood and timber, interchangeably. Timber plays an important role in the debate about how our cities should evolve to accommodate what the government hopes will be an increasing population in coming years without irretrievably damaging the environment.
One cubic metre of wood stores around one ton of CO2, making timber a construction material that can impact positively on the environment. Generally, timber buildings require less primary energy consumption (‘primary energy’ is the energy form that has not been subjected to any transformation process; it is energy contained in raw fuels and other forms of energy received as input to a system; it can be non-renewable or renewable) and have a lower Global Warming Potential (GWP) than concrete or steel buildings (the difference can be 25 per cent or more). Ideally, shouldn’t our buildings be like trees and our cities like forests?
Let’s build the same building with half the resources! (Hermann Kaufmann) .
2.2. Forests, Trees, Wood Products and Carbon Sinks: Grown by the Sun, Timber Is Materialized Solar Energy and an Efficient CO2 Accumulator
Everything begins with the forest that provides the material and is a decisive climate factor if wood is sourced in a sustainable way from well-managed forests. Residential building construction with wood is now changing, focusing on green supply chains and resource-optimized engineered systems. Timber construction is an efficient method of CO2 storage, as long as the material is obtained using responsible methods of forest cultivation (plantations) and from a certified source that is not too far away (to avoid transport-generated greenhouse gases).
A tree produces oxygen, and absorbs over 1.4 metric tonnes of carbon for every ton of timber g