Architecture, Building and Planning - Research Publications
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ItemA review of existing policy for reducing embodied energy and greenhouse gas emissions of buildings(ELSEVIER SCI LTD, 2022-09)The building sector is a significant contributor to global energy demand and greenhouse gas emissions and thus has a major role in combating climate change. To date, efforts to address this issue have focussed on reducing energy demand during building operation, resulting in significant reductions in this area. However, recent studies have shown that substantial improvements to operational energy efficiency have increased the relative significance of indirect or embodied energy demands and associated greenhouse gas emissions. Subsequently, policies addressing this next frontier of energy and emissions reductions are emerging. To understand different approaches and inform future development, this study reviews existing policy mechanisms targeting embodied energy and greenhouse gas emissions in the building sector for four countries – Australia, Canada, USA and United Kingdom. The study found that voluntary instruments dominate the policy landscape, with regulatory measures largely absent at national levels and confined to inconsistent application across lower levels of governance. Signals of change emerging from the analysis include growing private sector investment and increasing quantitative targets for reduction. The study concludes with the challenges facing this sector of energy governance, alongside recommendations for regulated caps, mandatory LCA reporting, prerequisite requirements in voluntary instruments, data accessibility and resolving methodological inconsistencies.
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ItemTowards a multiscale framework for modeling and improving the life cycle environmental performance of built stocks(Wiley, 2022-04-01)Cities are complex sociotechnical systems, of which buildings and infrastructure assets (built stocks) constitute a critical part. As the main global users of primary energy and emitters of associated greenhouse gases, there is a need for the introduction of measures capable of enhancing the environmental performance of built stocks in cities and mitigating negative externalities such as pollution and greenhouse gas emissions. To date, most environmental modeling and assessment approaches are often fragmented across disciplines and limited in scope, failing to provide a comprehensive evaluation. These approaches tend to focus either on one scale relevant to a discipline (e.g., buildings, roads, parks) or particular environmental flows (e.g., energy, greenhouse emissions). Here, we present a framework aimed at overcoming many of these limitations. By combining life cycle assessment and dynamic modeling using a nested systems theory, this framework provides a more holistic and integrated approach for modeling and improving the environmental performance of built stocks and their occupants, including material stocks and flows, embodied, operational, and mobility-related environmental flows, as well as cost, and carbon sequestration in materials and green infrastructure. This comprehensive approach enables a very detailed parametrization that supports testing different policy scenarios at a material, element, building, and neighborhood level, and across different environmental flows. We test parts of our modeling framework on a proof-of-concept case study neighborhood in Melbourne, Australia, demonstrating its breadth. The proposed modeling framework can enable an advanced assessment of built stocks that enhances our capacity to improve the life cycle environmental performance of cities.
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ItemThe economic value of low-energy housing(Taylor and Francis, 2016-01-01)This paper explores a new perspective towards understanding barriers to ascertaining the economic value of low-energy housing. It examines why the economic value of low-energy housing is less transparent in active markets; this is investigated from the valuation principle perspectives of embodied energy and operational energy in residential dwellings. The focus is placed on the composition of energy consumption associated with the housing product life cycle. Low operational energy of a dwelling is linked to consumer preference by the inter-temporal value estimate of expected benefits. However, “low” embodied energy housing is an ecological construct and does not appear to be directly linked to short-term market value or an expected (intuitive) economic motive. This “gap/disconnect”, alongside some practical “barriers” in the market economy, has created a challenge in deriving the economic value of low-energy housing. The barrier to economic value of low-energy housing is methodological and by adopting a life cycle approach to assessing and measuring energy in a house that incorporates embodied energy and operational energy, greater clarity can be achieved which may lead to a better informed market, enhancing transparency and allowing consumer choice to direct and value the broader benefits of low-energy housing.
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ItemQuantifying Australia's life cycle greenhouse gas emissions for new homes(Elsevier, 2020-10-01)Australia is going through a significant housing boom with approximately 200,000 new homes built each year; and significantly more are required on an annual basis to accommodate the estimated population growth of almost 36 million by 2050. The effects of climate change are increasingly being felt and responsive action is required for mitigation and adaption, which must include the greenhouse gas (GHG) emission implications of this new residential stock. Mitigation strategies have been predominantly focused on decreasing the operational GHG emissions associated with buildings, leaving the other life cycle stages, such as construction, largely ignored. To achieve national targets, such as zero net emissions by 2050, it is imperative to address GHG emissions mitigation from a life cycle perspective. This study found that based on current building practices one new detached dwelling built today will be responsible for roughly 545 tCO2e by 2050. This translates to the need to plant over 8,000 trees to offset these emissions, a figure it is safe to say, most homeowners will not achieve. This study modelled life cycle GHG emissions of all new detached dwellings constructed in Australia for a single year (2019) estimating 39 MtCO2e, which increases to 883 MtCO2e by 2030 and 3,654 MtCO2e by 2050. This is much higher than the current projections for Australia's total emissions by 2030 of 563 MtCO2e if a business as usual approach is followed, and the optimum target of 441 MtCO2e to meet emissions targets of 26% less than 2005. The results of this study suggest that housing-related GHG emission are underestimated by 60%, because of the absence of embodied GHG emissions being counted in emission projections. This emphasises that firstly, target and current GHG emission projections fail to consider emissions from a life cycle perspective, and primarily report findings based on operational data, which as this study has shown can lead to a misrepresentation of almost 96% of total life cycle GHG emissions.
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ItemIntegrating life-cycle GHG emissions into a building’s economic evaluation(Ubiquity Press, Ltd., 2020-07-13)Buildings contribute to greenhouse gas (GHG) emissions throughout their life—from material extraction and production to building demolition and disposal. Current GHG emission reduction efforts largely focus on building operation, typically ignoring embodied emissions. One of the main barriers affecting the uptake of embodied GHG emissions considerations is the uncertainty related to the economic value of a building with reduced life-cycle GHG emissions. A conceptual approach is presented for integrating the life-cycle GHG emissions of a building into an economic evaluation. A case study detached residential dwelling located in Melbourne, Australia, is used to demonstrate the approach using a range of economic valuation approaches. One approach, using a carbon tax, shows that the effective cost for a single household would be over A$2000 for the first year, rising to almost A$5000 in 10 years. Across the range of evaluation approaches considered, the total cost to the householder is found to be between A$4600 and A$7860. With the embodied GHG emissions accounting for over 66% of the case study’s life-cycle GHG emissions, the majority of the economic liability for the householder relates to the initial construction and ongoing material replacement of the building.