Stephen Pullen

Transport, housing and urban form: the life cycle energy consumption and emissions of city centre apartments compared with suburban dwellings

Buildings in cities and the activities carried out therein use a significant proportion of a nations energy consumption and produce substantial quantities of greenhouse gases in the process. Residential buildings are a large contributor, partially as a result of the transport and housing activities of households. In this study, life cycle analysis is used to calculate the total transport and housing energy and emissions from a sample of 41 households in apartment buildings in the city centre of Adelaide, Australia and compare them with suburban households. The purpose of this is to determine whether the urban density option of higher rise dwellings offers a lower environmental impact than conventional housing. The analysis includes delivered energy and greenhouse gas emissions generated by motorised travel and activities within the dwellings, and the energy and emissions embodied in household motor vehicles and the apartment buildings. The total delivered energy consumption of apartment households was found to be lower than suburban households due mainly to higher car usage, particularly in the outer suburbs. However, the analysis of total greenhouse gas emissions provided a somewhat different comparison especially when they were considered on a per capita basis. The total per capita emissions for apartment households varied considerably but, on average, exceeded those of both the inner and outer suburban households. This resulted from lower occupancy rates and higher emissions arising from higher dwelling operational and embodied energy consumption. Overall, it cannot be assumed that centralised, higher density living will deliver per capita emission reductions for residents, once the combined per capita life cycle emissions from housing and transport have been accounted for. A more vigorous educational, promotional and regulatory approach is required to achieve greater operational and embodied energy efficiency in apartment buildings to fully realise the emissions-reducing potential of such buildings in centralised locations.

Energy used in the Construction and Operation of Houses

Efforts to minimise energy consumption in houses have now broadened to the consideration of major life cycle energy inputs. This is part of a more holistic approach to energy analysis which takes into account the wider environmental impact of buildings. Research work is reported which looks at the relative proportions of operational and embodied energy of houses and compares this with previously published work. It is shown that embodied energy is a significant part of the life cycle energy consumption of houses and this justifies further consideration by designers. The amount of energy used during onsite construction is also addressed as part of life cycle energy consumption.

Embodied and operational energy consumption in the city

This study shows how estimates of energy consumption can be extracted from existing data sets and efficiently related to characteristics of the real property making up the discrete areas of the city. The study suggests that embodied energy consumption may be more significant than previously thought and suggests how estimates of embodied and operational energy may be used as a development control tool in the planning system.

Carbon-Neutral Commercial Building Development

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.

Factors influencing the retrofitting of existing office buildings using Adelaide, South Australia as a case study

Purpose – The purpose of this paper is to explore the barriers preventing investment in the re-use of low-grade multi-storey building stock in order to identify attributes that determine whether an existing building is suitable for retrofitting. Design/methodology/approach – Semi-structured interviews were undertaken with key industry practitioners to investigate existing practices and barriers facing low-grade building retrofits and what “ideal” multi-storey building features represent a successful investment opportunity. Findings – The findings showed that tenant commitment is necessary before any project goes ahead and that there exist many barriers influencing the investment decision. These include: high levels of asbestos found in existing buildings; changes in the National Construction Code necessitating enhanced fire safety and disability access; heritage listing; lack of awareness; overestimation of costs involved on simple and effective energy efficiency upgrades and change in tenant demands towa...

An Analysis of Energy Consumption in an Adelaide Suburb with Different Retrofitting and Redevelopment Scenarios

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.

Green Star Points Obtained by Australian Building Projects

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 is the use of a series of rating tools by the Green Building Council 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 the certification of Australian buildings by critically analysing a database of 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 other certified buildings in the Energy category. In contrast, 4 Star green buildings achieve more points in the Material category than 5 and 6 Star buildings. The study offers a useful reference for both property developers and project teams to obtain a better understanding of the rating scheme and consequently the effective preparation of certification documentation.

Assessing urban sustainability from a social democratic perspective: a thematic approach

Conventional typologies that seek to categorise indicators of urban sustainability tend to draw upon the neoliberal, silo approach for conceptualising sustainability, which positions sustainability as having economic, social and environmental dimensions. This approach has been critiqued for its inability to account for challenges to sustainability arising from interactions between social, economic and environmental variables. Models that are incapable of assessing dimensional interactions and their collective outcomes are also incapable of providing critiques that address entrenched structural challenges to sustainability. This paper proposes a new thematic approach based on Australian research to classify indicators for urban sustainability. The proposed approach shifts the categorisation of indicators from a neoliberal ontology to a social democratic foundation by proposing a model for assessing urban development relational to themes of amenity, accessibility, equity and environmental performance relative to resource conservation. The proposed approach is intended to be sensitive to integrating social, economic and environmental considerations with land use planning to improve the natural and built environments of communities.

Prospects for energy efficiency in Australian buildings: a review of current opportunities

This article explores the potential for energy performance contracting (EPC) to improve the energy consumption of existing buildings, using Australia as an example of a gradually maturing market. A review of EPC around the world is provided as the context and the question of the expansion of this activity into the non-commercial building sector is investigated. To determine the scope for expanded activities, a survey of energy efficiency organizations was carried out. It was found that some organizations were more prepared to extend beyond their current areas of activity and saw the potential of new markets, possibly by entering into partnerships with energy suppliers. Almost all the organizations surveyed were optimistic about growing their activity in the future. The article concludes by indicating considerable potential for action given changes to regulatory and market conditions.

Towards a More Holistic and Complementary Approach to Modelling Energy Consumption in Buildings

The need to reduce energy consumption in buildings is clearly recognised as a necessary contribution to the minimisation of greenhouse gas emissions. To complement the focus on the energy performance of individual buildings, this paper suggests additional approaches which include life cycle energy analysis in combination with urban energy mapping techniques. Commencing with an overview of energy consumption in the built environment, the paper draws attention to other components of urban energy consumption such as the embodied energy of buildings and infrastructure. The different approaches to modifying energy usage are placed in the context of scale in the built environment and complexity of urban energy improvements. Recent attempts to influence energy consumption patterns across this scale are referred to by using the city of Adelaide in South Australia as an example. Some research projects are described which take a range of approaches to modelling energy usage in buildings. These offer potential for analysing changes to overall energy consumption such as the retrofitting of buildings, selection of alternative dwelling forms and the design of urban redevelopments.