When it comes to sustainability in design and construction, Leyla Acaroglu writes, it is often immediately assumed that materials are one of the most important considerations. 
But more often than not, what you do with materials and the way they enhance or reduce other aspects of the building’s life is far more important. Over and over again, when a life cycle assessment (LCA) is conducted we find that the use phase dominates a buildings ecological footprint. LCA is a best practice environmental assessment methodology that analyses the impacts of a product or in this case building across its entire life, from the extraction of raw materials, manufacturing, transport, use through to end of life. Taking this whole-oflife approach allows us to identify the most significant impacts and reduce those before tackling the smaller issues – and in most cases, materials are the smaller issues.
Numerous life cycle assessments (just go to Google ‘scholar’ and type in LCA of a building to view a few) confirm that achieving increased efficiency in operating a building is the key to reducing its environmental impact. This doesn’t mean that ecopreferable materials should not be explored, adapted and used - but it does demonstrate that the most effective way to reduce the environmental impacts of a building lies in the decisions made around how it is used by its occupants.
So, from a life cycle perspective the things we do in a building (such as the amount of products we buy, the way we store and dispose of food, the amount of energy used and how we heat and cool it) will untimely dictate the overall environmental impact of the building - and all of these issues can be explored and addressed through life cycle thinking (LCT) in the design process. LCT allows a designer or decision maker to gain an insight into where potential environmental impacts might occur and then explore ways of reducing these through effective design decisions. For example, a life cycle approach to designing a low rise office block would be to firstly consider how the occupants can be encouraged to use the building in a more efficient way (such as making the stairs more appealing or increasing natural light and air ventilation that appeal to the occupant) once these elements have been considered, addressing the eco-effectiveness of the materials required to enable this can be considered.
As a sustainability advisor mainly working in the design industry, I am often asked to specify ‘eco friendly’ materials, but LCA demonstrates that there is no one-size-fits-all solution to material selection. The life span, intended use, durability, functionality and appropriateness of a material and design choice are the kinds of questions that need to be addressed first, at the inception of the design process in order to increase sustainability. I was recently in a ‘green’ building that had a range of ‘eco’ materials and energy efficiency options but none of the lights or cooling could be controlled by the user resulting in a significant impact through over lighting and air conditioned empty spaces. Looking at more advanced sustainable design in buildings includes considering how the design, of both the fabric and the spaces, affect the behaviours of the occupants. We know that badly designed spaces can make people unhappy, less productive or even sick, but how can design influence more sustainable and efficient behaviours? There are examples of buildings and products that engage the user in such a way that they encourage a subtle shift (such as wanting to use stairs instead of a lift or having to push down a button to fill a heating reservoir in a kettle). Design is a powerful tool that can influence users in all sorts of ways, but relying on materials to communicate sustainability is simply not enough.
As operational efficiency and user engagement improves in the design of a building, the selection of materials becomes more important. Or put another way, get operational efficiency and user engagement sorted and then work on material selection. The other issue that comes into play when choosing sustainable materials is that we often rely on our preconceived ideas about what is actually sustainable and this ‘environmental folklore’ is often a little bit flawed. Terms used to promote a material or product’s eco-credentials are often touted as biodegradable, renewable, recyclable and natural, and whilst these properties are good (rather than say being toxic or un-recyclable) they do not determine the econess of a material, they are simply properties that might or might not mean that you are reducing the overall impact by selecting them. In saying all of this, I’m not advocating for an abandoning of material considerations, more so, I’m calling for an expansion of the vision and scope of exploration that takes place across the entire design and construction process of a building. The wholeof- life impacts, longevity, durability, upgradability and adaptability of the entire structure and the elements within it are all crucially important ecodesign strategies that should always be considered when designing sustainably. Leyla is a lecturer at RMIT University and the director of award winning eco-design and sustainability consultancy Eco Innovators. She is a designer, social scientist, journalist and sometimes TV host.