• Energy Research

Abstract Few studies have evaluated the overall life cycle energy demand of residential buildings, including their embodied, operational and user-transport requirements. To our knowledge, none has quantified the life cycle cost associated with reducing each of the aforementioned energy demands. It is critical to evaluate both energy and financial requirements in order to provide effective energy saving solutions for actors of the built environment. This study quantifies the life cycle energy and cost requirements associated with 22 different energy reduction measures targeting embodied, operational and user-transport requirements. It evaluates a case study apartment building in Sehaileh, Lebanon. Embodied, operational and transport energy requirements are calculated over 50 years using a comprehensive approach. Life cycle costs are quantified using the net present value technique. Results identify the most cost effective energy reduction measures and discard some others which are financially prohibitive, namely the installation of photovoltaic panels and the use of hybrid cars. A number of recommendations for building designers, occupants, urban designers and planners and decision makers are provided based on the quantified benefits of each measure. This demonstrates the need for assessments with a broad scope and their potential to inform energy reduction strategies in the built environment.

Transitioning to renewable energy resources is necessary to address the energy and climate crisis and to be in accordance with UN Sustainable Development Goals (SDGs) 7, 11 and 13. Urban wind energy harvesting is still emerging mainly with the use of small wind turbines. Given their implementation challenges, positive and negative effects need to be weighed to make informed policy decisions and regulations. This systematic review evaluates the macro- and micro-scale environmental effects related to implementing small urban wind turbines (SUWTs). Although publications exist on diverse aspects of SUWTs, a review that addresses the broad range of identified environmental effects of SUWT implementations has been lacking until now. This review shows that while the study of the SUWTs’ environmental effects can build on the effects associated with large wind turbines, there are also significant differences. Given the heterogeneity of urban conditions, the implementation of SUWTs requires detailed local environmental assessment to characterise accurately most environmental effects, notably the net life-cycle primary energy performance and associated GHG emissions, raw materials depletion, recycling, safety, noise, visual and light pollution, and effects on urban wildlife. Effects that require further investigation and which possibly raise regulatory or social acceptance issues are identified and discussed. Policy relevance Harvesting urban wind energy can yield multiple environmental, efficiency and resilience benefits. However, several research and policy gaps remain to be addressed before deploying small wind turbines in urban contexts. These include: the need to quantify the net environmental gains of SUWTs based on their performance and life-cycle assessment; the structural implications of deploying SUWTs on existing buildings; the effect of SUWTs on local air quality and microclimates; the potential health and safety risks to those who may pass by; the effects of SUWTs on ecosystems; and the combined effects of SUWTs on people (e.g. noise or light annoyance). Further research and regulation can help to minimise the negative impacts and ensure social acceptability.

Abstract Cities and their building stocks result in huge environmental impacts which are critical to reduce. However, the majority of existing studies focus on operational requirements or on material stocks. To date, very few studies have quantified embodied environmental requirements of building stocks and spatialised them. This study describes a bottom-up approach to spatially model building stocks and quantify their embodied environmental requirements. It uses a highly disaggregated approach where each building's geometry is modelled and used to derive a bill of quantities. Construction assemblies relevant to each building archetype (derived based on land-use, age and height) are defined using expert knowledge in construction. The initial and recurrent embodied energy, water and greenhouse gas emissions associated with each material within each assembly are calculated using a comprehensive hybrid analysis technique. This model is applied to all buildings of the City of Melbourne, Australia. Results show that rebuilding the City of Melbourne's building stock today would require 904 kt of materials/km 2 (total: 32 725 kt), 10 PJ/km 2 (total: 362 PJ), 17.7 Million m 3 of embodied water/km 2 (total: 640.74 Million m 3 ) and would emit 605 ktCO 2 e/km 2 (total: 23 530 ktCO 2 e). This study demonstrates the breadth of the model outputs, including material stocks maps and breakdowns of life cycle embodied requirements by material, construction assembly, building and building typology at the city level. Using such model, city councils can better manage building stocks in terms of waste processing, urban mining and circular economy, as well as reducing embodied environmental requirements over time.

The Environmental Performance in Construction (EPiC) database is a free resource that contains embodied environmental flow coefficients for a broad range of construction materials using a comprehensive hybrid life cycle inventory approach.Detailed metadata for each material is available at www.epicdatabase.au by clicking on the DOI links for each material in the Excel version of the database.Cite as: Crawford, R.H., Stephan, A. and Prideaux, F. (2024) Environmental Performance in Construction (EPiC) Database, The University of Melbourne, Melbourne.

AbstractCities 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.

The circular economy is widely recognised as an effective model for mitigating waste production, preserving the functionality of resources and reducing dependencies on virgin materials. Transitioning Western Australia from a linear “take-make-waste” model to a circular economy is essential for achieving emission targets, reducing environmental impact, and generating economic value while maintaining people’s quality of life. While there is significant promise of resource efficiency gains, economic diversification, job growth and innovation, the implementation of a circular economy at multiple scales is inherently complex, highlighting the need for an evidence-based, system-wide approach that goes beyond current waste management strategies. We take a system-wide approach, focussing on several core aspects of a circular economy—resource inflows, built stocks and waste outflows—at the State, Greater Perth and municipal level. We evaluate WA’s capacity for circularity, the policy landscape, data and conceptual gaps and highlight key opportunities towards greater circularity and emission reduction across sectors and geographical scales. Finally, we outline a pathway towards a consistent, multi-scale indicator framework for building cross-sector capacity, and monitoring and driving circular outcomes.

The construction and operation of buildings is a major contributor to global energy demand, greenhouse gases emissions, resource depletion, waste generation, and associated environmental effects, such as climate change, pollution and habitat destruction. Despite its wide relevance, research on building-related environmental effects often fails to achieve global visibility and attention, particularly in premiere interdisciplinary journals – thus representing a major gap in the research these journals offer. In this article we review and reflect on the factors that are likely causing this lack of visibility for such a prominent research topic and emphasise the need to reconcile the construction and operational phases into the physical unity of a building, to contribute to the global environmental discourse using a lifecycle-based approach. This article also aims to act as a call for action and to raise awareness of this important gap. The evidence contained in the article can support institutional policies to improve the status quo and provide a practical help to researchers in the field to bring their work to wide interdisciplinary audiences.

Current assessments of residential building energy demand focus mainly on operational energy, notably in thermal terms. The embodied energy of buildings and the transport energy consumption of their users are typically overlooked. Recent studies have shown that these two energy demands can represent more than half of the life cycle energy over 50 years. This article presents a framework which takes into account energy requirements at the building scale, i.e. the embodied and operational energy of the building and its refurbishment, and at the city scale, i.e. the embodied energy of nearby infrastructures and the transport energy (direct and indirect) of its users. This framework has been implemented through the development of a software tool which allows the rapid analysis of the life cycle energy demand of buildings at different scales. Results from two case studies, located in Brussels, Belgium and Melbourne, Australia, confirm that each of the embodied, operational and transport requirements are nearly equally important. By integrating these three energy flows, the developed framework and software provide building designers, planners and decision makers with a powerful tool to effectively reduce the overall energy consumption and associated greenhouse gas emissions of residential buildings. © 2012 Elsevier B.V. All rights reserved.