Page 90 - Materials Chemistry, Second Edition

Life cycle assessment: applications in the built environment

ments than equivalent western world housing (Horne and Hayles 2008). This study also indi- 77
cated that mandatory building codes are effective mechanisms for setting benchmark standards
for aspects of building environmental performance. Meanwhile, the issue of regulating for
embodied energy or end-of-life has yet to be taken up significantly by policy makers.
In contrast, the voluntary regulatory and performance arena is marked by a relative plethora
of rating tools, guidelines and checklists for ecologically sustainable development (ESD).
Although rating tools invariably started with attempts to improve energy efficiency, more
recently, tool development has shifted into the broader arena of environmental sustainability
performance. The National Australian Built Environment Rating System (NABERS) and the
New South Wales Building Sustainability Index (BASIX) identify water use and stormwater as
major issues in addition to energy and greenhouse gases, and the Green Building Council of
Australia’s Green Star suite of tools identifies a range of environmental performance issues to
be considered. A next logical step may be for regulation to follow into this wider area of envi-
ronmental performance. However, many of the ‘sustainability’ rating tools are still in their
infancy. Any regulation must be built upon a robust evidence base and tools used in this should
therefore be:
s based on underlying science
s comprehensive in terms of the impact scope assessed
s usable and practical
s transparent in methodology and algorithms
s internally consistent and valid
s suited to climate, cultural and other factors in the area to which they apply
s not overly resource-intensive in operation
s clear in stepping up performance levels over time to those required by long-term goals
s reviewed and updated regularly to reflect developments in knowledge.
LCA-based tools have existed since the 1990s, developed with buildings assessment appli-
cations in mind or specifically to address buildings environmental assessment or design issues.
For example, the Boustead model has been extensively used for building assessment, and com-
puter-aided design (CAD)-related tools have been developed, such as BEES, Building Design
Advisor (USA) and, more recently, LCA Design (Australia). Athena and Optimise were both
developed in Canada, to provide support in designing buildings with the environment in
mind; there are numerous other examples. Ecospecifier was developed in Australia as a guide
to environmentally sustainable and healthy products, materials and technologies for the con-
struction sector, specifically targeted to the needs of decision-makers and specifiers. However,
like the main rating tools (e.g. LEED in the USA, BREEAM in the UK and Green Star in Aus-
tralia), Ecospecifier borrows from LCA but does not maximise its use.
Since LCA fulfils the requirements listed above, there is a prima facie case for the increased
use of LCA in contributing to regulation and policy for environmental performance of build-
ings, underpinned by international standards. In particular, LCA provides a scientific basis for
the way in which environmental impacts are assessed and combined, and provides rigorous
and transparent information on these impacts. For example, it can be used to estimate the
total energy consumption of buildings and even the specific fossil-based energy component. In
turn, this assists in specifying the life cycle profile – in this case, of greenhouse gas emissions.
It can specify ‘life cycle total fossil fuel consumption’ (as opposed to simply ‘energy efficiency’)
and other environmental impacts of materials and indoor environmental quality (e.g. indoor
climate, air and daylight). If these impacts are to be regulated, LCA will be important. The fol-
lowing sections illustrate the use of LCA in a range of built environment applications over
recent years, current applications and prospects for future applications.

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