Reduced water consumption is one of the objectives of many towns and cities as part of the trend towards more sustainable settlements. Information on comprehensive water usage is required for formulating conservation and management strategies. Whilst buildings are directly responsible for only 12% of global water consumption, they can indirectly account for a much more significant proportion of total water demand due to the production of construction materials as well as the goods and services purchased by their occupants. This paper analyses both direct and indirect water consumption of a conventional Australian residential building and its occupants over a 50-year period. Input–output analysis is used to comprehensively determine total water usage. The results show that the direct water consumption to operate the house is only 6.4% of the total, with a further proportion embodied in the materials of the dwelling. The water embodied in consumable items, especially food, is the most significant, representing 46% of total household water demand. Policies for minimizing water consumption should address more than just direct water usage and the findings used to influence the design of urban living in the future. La réduction de la consommation en eau est l'un des objectifs de nombreuses villes, grandes et moins grandes, dans le cadre de la tendance actuelle à aller vers des habitations plus durables. Il est nécessaire de pouvoir disposer d'informations sur l'ensemble des usages qui sont faits de l'eau pour pouvoir formuler des stratégies de préservation et de gestion. Alors que les bâtiments ne sont directement responsables que de 12% de la consommation mondiale en eau, ils peuvent représenter indirectement une part beaucoup plus importante de la demande totale en eau, du fait de la fabrication des matériaux de construction comme des biens et services achetés par leurs occupants. La consommation en eau directe aussi bien qu'indirecte est analysée sur une période de 50 ans, en utilisant comme étude de cas un immeuble résidentiel australien classique et ses occupants. L'analyse des entrées et des sorties est pleinement utilisée pour déterminer l'usage total de l'eau. Les résultats montrent que la consommation directe en eau pour faire fonctionner la maison ne s'élève qu'à 6,4% du total, une part supplémentaire virtuelle étant constituée par les matériaux de l'habitation. L'eau virtuelle des produits consommables, en particulier des aliments, est la plus importante, représentant 46% de la demande totale en eau de l'habitation. Les politiques visant à réduire au minimum la consommation en eau devront aller au-delà du simple usage direct de l'eau, et ces résultats devront être utilisés pour influer à l'avenir sur la conception de la vie urbaine. Mots clés: eau virtuelle consommation des ménages analyse du cycle de vie de l'eau immeubles résidentiels consommation en eau

The green building trend has increased rapidly worldwide in recent decades as a means of addressing growing concerns over climate change and global warming and to reduce the impact of the building industry on the environment. A significant contribution in Australia has been the use of a series of rating tools by the Green Building Council of Australia (GBCA) for the certification of various types of buildings. This paper reviews the use of the Green Star system in Australian building construction and investigates the potential challenges involved in acquiring such certification for Australian buildings, by critically analyzing a database of the most recently certified GBCA projects. The results show that management-related credits and innovation-related credits are the easiest and most difficult, respectively, to obtain. Additionally, 6 Star green buildings achieve significantly higher points than do other certified buildings in the energy category. In contrast, 4 Star green buildings achieve more points in the material category than do 5 and 6 Star buildings. The study offers a useful reference for both property developers and project teams that can help them obtain a better understanding of the rating scheme and consequently aid in the effective preparation of certification documentation.

It is well recognized that the construction industry is one of the largest contributors to global greenhouse gas emissions. This research investigates achieving carbon neutrality in commercial developments. A case study approach was adopted to gain an in-depth analysis of the first commercial building claimed to be carbon neutral in Australia. Key participants were interviewed, and this was followed by a review of the project specification. The analysis focuses on practices to achieve carbon neutrality in commercial developments, such as standard setting, measurement, materials selection, construction techniques, and knowledge. Results showed that a carbon-neutral commercial building can be achieved even though there are a number of challenges, such as lack of maturity in working definitions and subsequent standards to measure carbon neutrality. The selection of appropriate materials and relevant knowledge are critical in achieving carbon neutrality in commercial building developments. This study provides a useful reference for future carbon-neutral commercial developments.

Office buildings constitute a significant proportion of the non-residential building stock. In recent years, various rating tools have been developed to foster green office building development. The Green Building Council of Australia (GBCA) has developed the Green Star - Office rating tools for this purpose. There are an increasing number of stakeholders adopting these tools to showcase their efforts in sustainable development. This research focuses on the challenges and barriers in obtaining GBCA ratings in Australian Office buildings. To accomplish this, the scoring sheets from the rating of 264 certified office buildings were collected and critically analysed. The findings indicated that credits related to the attributes of innovation, ecology and energy are comparatively difficult to achieve. It was also found in this study that a large number of projects did not apply for the specific credits of refrigerant global warming potential, re-use of façade, topsoil and fill removal from site, and individual comfort control. This study provides a useful reference to both the property developer and the Green Building Council of Australia for green building developments in the future. In particular, the findings provide useful inputs to the development of the next generation of green building rating tools.

Decarbonising the urban built environment for reaching carbon neutrality is high on the agenda for many cities undergoing rapid expansion and densification. As an important urban form, precincts have been increasingly focused on as the context for urban redevelopment planning and at the forefront for trialling carbon reduction measures. However, due to interplays between the built forms and the occupancy, the carbon performance of a precinct is significantly affected by morphological variations, demographical changes, and renewable energy system deployment. Despite much research on the development of low-carbon precincts, there is limited analysis on aggregated effects of population growth, building energy efficiency, renewable energy penetration, and carbon reduction targets in relation to precinct carbon signature and carbon neutral potential for precinct redevelopment and decarbonisation planning. In this paper, an integrated carbon assessment model, including overall precinct carbon emissions and carbon offset contributed by precinct-scale renewable energy harvesting, is developed and applied to examine the lifecycle carbon signature of urban precincts. Using a case study on a residential precinct redevelopment, scenario analysis is employed to explore opportunities for decarbonising densification development and the carbon neutral potential. Results from scenario analysis indicate that redevelopment of buildings with higher-rated energy efficiency and increase of renewable energy penetration can have a long term positive impact on the carbon performance of urban precincts. Meanwhile, demographical factors in precinct evolution also have a strong influence on a precinct’s carbon neutral potential. Whilst population size exerts upward pressure on total carbon emissions, changes in family types and associated consumption behaviour, such as travelling, can make positive contributions to carbon reduction. The analysis also highlights the significance of embodied carbon to the total carbon signature and the carbon reduction potential of a precinct during densification, reinforcing the notion that “develop with less” is as important as carbon offsetting measures for decarbonising the precinct toward carbon neutrality.

Improving energy efficiency of the existing dwelling stock of towns and cities will increasingly be part of the effort to moderate fossil fuel energy consumption in the decades to come. At the same time, residential areas may be subject to densification to better utilise the existing urban infrastructure whilst accommodating a larger population. The analysis of energy consumption arising from these trends offers the potential for optimising built forms and assisting in development decisions for urban renewal to encourage lower energy outcomes. This article describes the application of a model which uses a life cycle approach to the analysis of energy consumption in a residential suburb. The results indicate that the inclusion of embodied energy expended during redevelopment can be substantial and should be considered when modelling future energy consumption scenarios.