Summary Reader Response Draft 1
IMPORTANCE OF CONDUCTING LIFECYCLE ASSESSMENT (LCA) ON GREEN BUILDING MATERIALS
California’s
Department of Resources Recycling and Recovery's article, Green Building
Materials (n.d.) states that using green building materials encourages the
conservation of waning non-renewable resources globally, reduces building
owners' and occupants' costs throughout the building's lifecycle, helps
conserve energy, improve occupant productivity and health, and provide enhanced
design flexibility. Making early design selections and establishing strategies
are essential for green building materials (Froeschle, 1999).
The environmental assessment of materials and buildings is convoluted due to its subjectivity and complexity (Saghafi and Teshnizi, 2011). The choice of building materials influences the overall performance of a building, and the materials' impacts should be considered "from cradle to grave" (Song and Zhang, 2018, p. 2). The Lifecycle assessment (LCA) is a multifaceted system of qualifying and comparing inflows of materials, energy usage, and emission outputs with regard to building materials at varying spatial scales and contexts (Finnveden et al., 2009, as cited in Ding, 2014).
LCA does have its limitations in evaluating green building materials, due to data limitations (Finnveden et al., 2009). However, given the criticality of green building materials on sustainability, it is imperative to have a complete lifecycle outlook toward selecting green building materials to holistically determine responsible material usage, energy consumption, and building emissions.
1. Impacts of LCA on Material Usage and
Building Emissions
An estimated 24% of global raw materials were consumed by the construction
industry (Bribian et al., 2010). Throughout their lifecycle, buildings impact
the environment, and the building materials used will affect their overall
performance. Sustainable building materials are often perceived as materials
that are natural. However, materials regarded as natural are not necessarily
green materials: Asbestos, once added to some building materials, is now banned
due to its carcinogenic properties; radon, a radioactive gas emitted by some
stones in buildings, can be harmful to inhale; or turpentine, a solvent
obtained by distilling tree resins, can negatively impact human health
(Franzoni, 2011).
Thus, it is crucial for building stakeholders to understand and conduct thorough LCA of the building materials used. This allows them to eliminate building materials with negative environmental emissions and impacts.
2. Impacts of LCA on Energy Consumption and Building Emissions
Energy consumption and carbon emissions are other critical considerations for
green building materials. Buildings use 30 – 40% of all primary energy globally
and they are responsible for 40 – 50% of greenhouse gas emissions (Asif, Muneer, and Kelley, 2007). Through lifecycle analysis, operational energy
demonstrates a major share (80–90%) in the lifecycle energy usage of buildings,
followed by embodied energy (10–20%), then demolition and other processes
(negligible) (Ramesha, Prakasha, and Shukla, 2010). The LCA of corporate
buildings constructed in China using steel and concrete depicts embodied energy
and environmental emissions of steel-framed buildings to be better than
concrete-framed buildings (Xing, Xu, and Jun, 2008). Nevertheless, due to the
higher thermal conductivity of steel compared to concrete, operational energy
consumption and greenhouse gas emissions were larger for steel-framed buildings,
hence their overall lifecycle energy consumption and carbon footprint were
slightly higher.
LCA of a building’s energy consumption and carbon emissions is expedient to
access strategies to reduce them. In doing so, the areas of a building’s
lifecycle that have higher energy demands and carbon emissions can be
identified and addressed.
3. Limitations & Future Prospects of LCA
Due
to data limitations, LCA tools are inadequate in verifying the environmental
impacts throughout a building’s lifecycle (Cole, 2010, as cited in Ding, 2014).
These limitations include data variability, incomplete or erroneous data, lack
of precision and inaccurately or wrongly implemented digital algorithms, and
relationship (Finnveden et al., 2009).
LCA does not adequately address how well a
product or building material can be recycled (Saghafi and Teshnizi, 2011). The
effects of recycling are handled through allocation, which creates flaws in accuracy
based on assumptions of a material’s future recyclability. A theoretical
example of ore-based steel beams, which can be considered a green building
material due to their recyclability, illustrates this (Thormark, 2001). With
available LCA allocation methods, varying assessment impacts can range from; the
dismantling, and upgrading of transportation processes associated with recycling steel
to; all impacts from ore-based steel production, future waste treatments, and associated
transport emissions. This demonstrates the unpredictability and uncertainty
that may arise when using LCA to determine the impacts of green building materials.
Due to the lack of predictive data and inaccurate relationships established, the arbitrary assessments of LCA may give building stakeholders an impression of being descriptive rather than being based on assumptions of the future (Thormark, 2001).
However, LCA methodologies have been cultivated over the last decades
(Finnveden et al., 2009). Current developments in databases, quality assurance,
consistency, and harmonisation of methods contribute to this. With growing
comprehension and interest in developing LCA methodologies, more innovative research
and solutions can be conducted. Greater accuracy and precision in analysing
building material impacts, especially green building materials, would allow for
enhanced holistic considerations of building emissions, energy consumption, and
usage of materials.
4. Conclusion
Despite their upfront or perceived benefits, the longstanding effects of using green
building materials may result in an overall disservice to the environment.
Therefore, building stakeholders must be able to discern the overarching
impacts of their materials and buildings throughout their lifecycles. This is
attainable through the use of LCA, where building emissions, energy
consumption, and materials used can be thoroughly and holistically analysed.
Green building materials can then be acutely selected and used responsibly to
provide an enduring boon.
Word Count (Excluding Paragraph
dividers): 876 Words
References
https://doi.org/10.1016/j.buildenv.2005.11.023
Bribián, Z.I., Capilla,
A.V., & Usón, A., A. (2011). Life cycle assessment of building materials:
Comparative analysis of energy and environmental impacts and evaluation of the
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California’s Department of Resources Recycling and Recovery (CalRecycle). (n.d.). Green building materials. CalRecycle. https://calrecycle.ca.gov/greenbuilding/materials/
Ding, K.C. (2014). Life
cycle assessment (LCA) of sustainable building materials: an
Overview. Eco-Labelling
and Case Studies, 38-62.
https://doi.org/10.1533/9780857097729.1.38.
Finnveden,
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Franzoni, E. (2011).
Materials selection for green buildings: Which tools for engineers and
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Froeschle, L. M. (1999).
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Ramesh, T., Prakash, R. & Shukla, K.K. (2010). Life cycle energy analysis of buildings: An overview. Energy
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https://doi.org/10.1016/j.enbuild.2010.05.007
Saghafi, M. D., and
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Thormark, C. (2001).
Recycling Potential and Design for Disassembly in Buildings [Doctoral
dissertation, Building Science].
https://www.lunduniversity.lu.se/lup/publication/da69c22d-8bc0-4b97-b95d-d11751499304
Xing, S., Xu, Z., & Jun,
G. (2008). Inventory analysis of LCA on steel- and concrete-construction office
buildings. Energy & Buildings, 40(7), 1188–1193. https://doi.org/10.1016/j.enbuild.2007.10.016
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