green building materials

Mudbrick, centuries old material, is making a comeback due to its beauty and usually low environmental impact

Behind the trees is a green roof, designed by associate Ben Nicholson.

Recycled timber decking

Environmental impact assessment:  The building industry is responsible for a significant portion of total global environmental damage. When assessing the environmental impact of building materials, we consider:

• Depletion of a limited resource
• Loss of biodiversity
• Resource degradation (includes effects on water, soils, etc)
• Energy consumption (embodied energy)
• Toxicity
• Re-use or recyclability
• Ethical treatment of workers and or animals

Life cycle analysis (LCA) measures the environmental impact of a material over its lifespan, including extraction of raw material, manufacture, transport, construction, use and disposal (or re-use). This is a complex task and we use an online tool to help, “Ecospecifier”  (www.ecospecifier.com.au), as well as certifiers GECA (Good Environmental Choice Australia) (www.geca.org.au), FSC (Forest Stewardship Council), Green Building Council of Australia green star system and the ABGR (Australian Building Greenhouse Rating scheme). 

Comparison between materials is not always simple, some examples:

Energy accounting: A concrete floor consumes more energy in production than a timber floor. However, a concrete floor correctly designed for passive solar can reduce the energy used in heating & cooling a house over its lifespan. 

Process accounting: A floorboard cut from high biodiversity forests and kiln dried has high environmental impact. Another floorboard cut from sustainable agroforestry and solar dried has relatively low environmental impact. The two floorboards may look identical.

Comparison across different criteria: For example, local treated plantation pine has moderate embodied energy, significant toxicity but of low biodiversity impact if grown on ex grazing land. Imported rainforest timber has lower embodied  energy, low toxicoty and very high impact on biodiversity. Priorities need to be made.  By the way (not that we like treated pine), ecoliving design places biodiversity impact as the highest priority because biodiversity loss is difficult or impossible to recover.

What do we do?

If you ask us for a new building design, reno, or landscape design, where possible we specify materials of similar price yet reduced environmental impact, compared to conventional construction. If you are prepared to pay more for a higher level of eco construction, we spend extra time with you discussing options and resolving choices.