Page 95 - Materials Chemistry, Second Edition

Life Cycle Assessment: Principles, Practice and Prospects
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following the Olympics project. Without a clear incentive for designers or builders to carry on
such work, the use of LCA in this type of application was extremely limited until the Green
Building Council Green Star and other building rating tools became prominent, and demand for
environmental information on building materials rose once again. This is unfortunate as some
of the tools developed in the early to mid-1990s, such as LCAid, were not further developed. Had
their development continued, this would have placed LCA in a strong position to meet current
demands for building LCA modelling. Instead, they withered for want of a market.

7.2.2 Case study 2: scoping impacts of building materials in Australia
The federal Department of the Environment and Heritage commissioned this study in 2005 to
provide information to the Australian Building Codes Board following the inclusion of ‘sus-
tainability’ in the inter-governmental agreement that underpins the Building Code of Aus-
tralia. This case study is drawn from the resulting report (DEWR 2007). The research aimed to
identify and quantify the range of environmental impacts associated with the building fabric
and to identify possible measures that could improve the sustainability of building materials
across the life cycle or supply chain.
The study examined the life cycles of key materials that make up the building fabric. The
choice of materials affects operational performance, although the link is not always precise or
direct. For example, two buildings with apparently identical materials can have dramatically
different operational energy performance depending on design, detailing and construction.
The buildings themselves and fit-out materials, including operational aspects of building use
such as lighting, space heating or cooling and use of appliances, were excluded from the study.
Infrastructure construction such as roads, bridges, services and materials used outside the
building (e.g. paving, driveways and fencing) was also excluded.
Materials flows for the Australian construction sector were established using historical data
collected by BIS Shrapnel over the years 1994 to 2005 for four sectors: new separate houses,
improvements to separate houses, multi-residential construction and non-residential construc-
tion. This data was used in combination with the CSIRO Australian Stocks and Flows Frame-
work (ASFF), a population-driven materials flow model for the Australian economy, to provide
the base case scenario, which was set at 2005. The ASFF was used to project likely trends in the
use of building materials for the next 50 years (until 2055), extrapolated from historical trends
over the last 20 years using the materials flows identified. The resulting materials flow data was
then assessed with SimaPro software using inventory data relevant to Australia (with input
from the Australian building products sector) to estimate the potential environmental impacts
occurring from production, use and disposal of materials – now and into the future.
A business-as-usual model, with unabated growth in house demand, was developed for
comparison with a range of scenarios including the base case to test the relative impacts of dif-
ferent strategies to reduce environmental impacts. The total list of scenarios were:
s unabated growth in house sizes (business-as-usual)
s base case (set at 2005)
s increased shift to multi-unit residential properties
s reduction in demolition rate of houses
s slow lowering of house size
s increased number of people per household
s fast lowering of house size
s combined reduction in housing size and increase in persons per household.

Where clear trends were not observable in the historical period, scenario values were fixed
at the 2005 value. The average size of new houses has grown significantly, by about 40%, over

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