Identifying attributes contributing to environmental sustainability of public-private partnership infrastructure projects

Due to increasing demands for new infrastructure and an aim to reduce initial public investment, Australian government agencies are increasingly using public-private partnerships (PPPs) as a form of delivery for infrastructure projects. Environmentally, there is growing pressure for the building industry in general to become more sustainable. Moreover, as the built environment continues to grow each year, the performance of buildings as a whole will need to continually improve purely for national energy consumption to remain stable. Based on a systematic and extensive review on relevant literature, this paper has identified the key attributes that will influence the environmental sustainability of infrastructure completed through a PPP. The key attributes are grouped into five groups defined by whom or what has the majority of control over the attribute. Meanwhile, the key attributes are explored and their influence on environmental sustainability justified. This paper was able to not only identify significant factors involved in creating environmental sustainability in infrastructure PPPs, but also trends of the key attributes. It has been found that (1) the longevity of the contract in a PPP project allows greater innovation into environmental sustainability than traditional methods of procurement, (2) innovation is a requirement for the improving upon environmental performance in the built environment, (3) improvements to environmental sustainability relies upon a positive relationship between economic and environmental benefits, and (4) the key attributes for PPP projects are decided upon relatively early in the contract. Due to space limit, detailed discussion on each of the identified attributes is not provided in this paper. Nonetheless, further research direction is discussed.

Integrated approach of sustainability and climate change adaptation in a metro project

The new Melbourne Metro underground rail project will leave a legacy long into the future, with an estimated design life which will extend beyond 100 years. As such it is extremely important to consider the mitigation of any environmental impacts, providing a sustainable outcome. It is also essential to pre-empt required adaptation of buildings and infrastructure in the future against the impact of changes in the local climate. Designing a metro system in the age of climate change provides the opportunity to go beyond standard specifications and compliance requirements, creating innovative sustainable and climate resilient design outcomes. On the contrary, constructing an underground metro project presents various design challenges fuelled by complex constraints, many uncertainties and risks. This paper will review the methodology used to integrate environmentally sustainable principles and resilient design for climate change adaptation, within the concept development phase of the Melbourne Metro Underground Rail Project.

The impact of occupant behaviour on residential greenhouse gas emissions reduction

In 2011-12, greenhouse gas emissions from the Australian residential sector were 101.6 Mt and are expected to grow by 38% by 2050. In order to reduce these emissions, much emphasis has been placed on increasing the energy efficiency of buildings and appliances. Occupant behaviour, however, is probably the single most significant factor which determines energy use and emissions. This paper describes research undertaken to rank the most common occupant behaviours, based upon their impact on greenhouse gas emissions associated with residential energy use, in an architect-designed house in Australia. The occupant behaviours investigated were changing: the heating and cooling temperature set points, window openings, external blind use and lighting use. Simulations were carried out using Primero and EnergyPlus software. Based on the simulation results of greenhouse gas emissions, the following ranking of overall influence (from most influential to the least) has been determined: external blind use was one of the most effective measures to reduce emissions. Cooling set point temperature was similarly important with the magnitude of impact depending on the set point e.g. a 2°C increase had an impact comparable to the use of external blinds. The impact of the heating set point temperature was also dependent on the set point and overall slightly lower compared to the cooling set point temperature. Lighting use was the least influential parameter in the context of this study.

Climate change and our heritage of low carbon comfort

This paper examines the viability of maintaining a heritage of low carbon comfort as an alternative to the energy intensive comfort regime of mechanical air conditioning. In many parts of the world, the carbon footprint of buildings is increasing significantly due to the widespread adoption of air conditioning. Current trends around indoor comfort are unsustainable, and alternative, less energy intensive comfort regimes need to be maintained or cultivated. To date, studies on this topic in heritage and preservation studies have focused on the architectural designs of 'passive cooling'. This paper seeks to expand this conceptualisation of 'cool living heritage' to incorporate other forms of material culture and comfort practice.

The etymology of a colourful design language: How do we determine what informs architect’s colour choices?

The development of materials and visualization technology is transforming the colour palettes of cities. As architects have significant roles in determining the appearance of buildings that contribute to city colourscapes, it might be expected that they have considerable colour knowledge. However, there is largely an absence of colour training in built environment education outside of interior design, meaning architects are likely making colour choices based on practical rather than theoretical knowledge. This prompts the question: what informs the architect’s colour choices? While colour has been studied in a broad range of disciplines, few studies have focussed on the built environment and even fewer on how and why built environment designers choose colours. This article explains the origins and development of a framework for understanding factors that influence architects’ uses of colour. The framework has informed a national survey in Australia to determine how personal and educational experiences have affected the use of colour.

Modelling greenhouse gas emissions for Australian residential building construction

International pressure to reduce greenhouse gas emissions has forced many countries to look beyond 'demand side' measures. Several industry sectors are examining indirect requirements for energy and other resources that involve significant greenhouse gas emissions. The operation of buildings is responsible for approximately one quarter of greenhouse gas emissions in Australia. Moreover, he construction process consumes vast quantities of raw materials and complex goods and services each year. Each of the processes required for the provision of these products requires energy, and most of this is fossil fuel based. A national model of greenhouse gas emissions is required for residential building construction, to indicate where emissions reduction strategies should focus. A disaggregated input-output model is developed for the Australian residential building construction sector, and recommendations are made about how this model can be used in the development of policies of emissions mitigation for both the sector and individual residential buildings.

Web enabled just-in-time salvaged material management for demolition projects

The demolition activities of buildings produce numerous environmental pressures as a large proportion of demolition waste materials are sent to landfill directly in many projects. Web-based waste exchange systems could provide right solutions for releasing these pressures. Because the approaches adopted in current waste exchange systems are inefficient, these systems cannot generate waste exchange, not achieving their final goal, environmental protection. The Just-in-time (JIT) philosophy has been applied in the manufacture industry for decades and it is proven to be effective to eliminate or minimise inventory during production. This research aims to adopt the JIT philosophy into a demolition project management informapon system so that the system is more efficient in handling waste exchange. The system structure, key components and Just-in-time adoption are proposed and identified. Finally, a proto typed system is demonstrated.

Architecture, ethics and sustainability - an exploration

Globally we are grappling with the concept of sustainability. What does it mean and how should we respond to ensure that the planet and its ecosystems survive? While the problem of living in a sustainable way must be addressed by all sectors of society, architects are arguably in the 'front line' because of the impact of buildings in terms of resource use and waste generation. Most definitions of sustainability are unhelpful because of their wordiness, lack of detail or ambiguity. Others distort the concept of sustainability to allow business-as-usual (i.e. unsustainable) activity to continue. Using one particular model of sustainability, this paper explores the apparent contradictions between architectural practice in the residential sector, 'sustainable' housing and the desire to behave ethically. The paper begins with definitions of sustainability and ethics, together with some guiding principles. The literature examining the ethics of sustainable architecture is then reviewed. Two indicators are suggested to make a broad-brush assessment of sustainability. Current practice in Australian residential architectural design, both mainstream and 'green', is then critiqued against these indicators. Finally, some practical options for a practising architect faced with a client, who wants an 'unsustainable' house, are briefly explored.

Building energy efficiency labeling programme in Singapore

The use of electricity in buildings constitutes around 16% of Singapore's energy demand. In view of the fact that Singapore is an urban city with no rural base, which depends heavily on air-conditioning to cool its buildings all year round, the survival as a nation depends on its ability to excel economically. To incorporate energy efficiency measures is one of the key missions to ensure that the economy is sustainable. The recently launched building energy efficiency labelling programme is such an initiative. Buildings whose energy performance are among the nation's top 25% and maintain a healthy and productive indoor environment as well as uphold a minimum performance for different systems can qualify to attain the Energy Smart Office Label. Detailed methodologies of the labelling process as well as the performance standards are elaborated. The main strengths of this system namely a rigorous benchmarking database and an independent audit conducted by a private accredited Energy Service Company (ESCO) are highlighted. A few buildings were awarded the Energy Smart Office Label during the launching of the programme conducted in December 2005. The labeling of other types of buildings like hotels, schools, hospitals, etc. is ongoing.

Urban heat island and its impact on building energy consumption

Urban areas tend to have higher air temperatures than their surroundings as a result of man-made aiterations. This phenomenon is known as the urban heat island (UHI) effect. UHI is considered to he one of the major problems encountered by the human race this century. Solar radiation that is absorbed during the day by buildings is re~emitted after sunset creating high temperatures in urban areas. Also, anthropogenic heat sources such as air conditioners and road traffic add to the rise in temperatures, A number of
studies have indicated that UHI has a significant effect on the energy use of buildings. In mid- and low-latitude cities, heat islands contribute to urban dwellers' summer discomfort and significantly higher air-conditioning loads. This chapter summarizes and reviews the latest research methodologies and findings about the effect of increased temperatures on the energy consumption of buildings. The latest developments in the heat island mitigation strategies are remarkable, However, more attention needs to be
given to the implementation and testing of these strategies in full-scale buildings.

Office building characteristics and the links with carbon emissions

Purpose – The purpose of this paper is to present research which analysed energy consumption in the Melbourne central business district (CBD) office stock and examined all buildings to identify CO2 emissions in 2005. The rationale was that, by profiling a large group of buildings, it would be possible to identify characteristics of the stock. For example, do older buildings typically emit more CO2 per square metre than newer buildings?
Design/methodology/approach – This research conducted a detailed analysis of all Melbourne CBD office stock to identify which patterns and trends emerged regarding building characteristics and carbon emissions. The study examined variables such as building size, number of employees, occupancy levels, physical characteristics and building age.
Findings – By examining all office stock and aggregating data, the results confirm that it is possible to identify general physical building characteristics and carbon emissions. This research confirmed that clear relationships existed within the Melbourne CBD office stock in terms of building size, age and the density of occupation in relation to CO2 emissions.
Originality/value – Practitioners can apply this knowledge to the professional advice they give to clients to assist in achieving increased energy efficiency in the office stock, for example in refurbishment being conscious that smaller buildings will be generally less energy-efficient than larger ones.

The structural and behaviourial barriers to sustainable real estate development

Sustainable real estate development appears, on literal translation of both terms, to be an oxymoron - however it is a concept that the real estate profession needs to embrace knowledgably. On one hand it can be argued that real estate development is required for continued economic growth and the adoption of sustainability measures is required to mitigate climate change and global warming. Over the last few years there has been growth in the number of sustainability tools available to designers and operators of buildings. For example, in the US the LEED scheme enables designers to assess the environmental impact of their design and to benchmark the sustainability of the design against industry recognised criteria. LEED follows a similar format to the UK’s Building Research Establishment Environmental Assessment Method (BREEAM) introduced in 1990 and the Australian ‘GreenStar’ introduced in 2004. Even though there are an increasing number of sustainability tools available to designers, it still remains that the degree of uptake of the tools has been sporadic. This paper discusses the barriers to sustainable real estate development. Firstly it identifies the barriers to uptake and secondly it establishes the structural barriers in the market which prevent the wider uptake of tools.

Convection suppression in an attic shaped enclosure

In recent times there has been growing interest in the integration of solar collectors, for water heating, into the façade of buildings. However, the design methodology of these devices remains largely the same as typical “stand-alone” collectors. As such it is still common for materials with a high thermal resistance to be used for insulating the rear surface of these collectors.

Unlike a “stand-alone” solar collector that is exposed to the atmosphere at all faces; a building integrated system allows the opportunity for air to act as an insulator at the rear surface of the solar collector. The use of convection suppression devices has been widely discussed in the literature as a means of reducing natural convection heat loss from the front surface of glazed solar collectors. However in this study the use of baffles in an attic was examined as a means of suppressing heat loss by natural convection from the rear surface of a roof-integrated solar collector. The aim of the study was to examine whether the use of baffles would allow the cost of building integrated collectors to be reduced by removing the cost of insulating material.

To determine the effect of baffles in the attic space at the rear surface of the collector, a 3-dimensional triangular cross sectioned enclosure with a vertical aspect ratio of 0.5 and a horizontal aspect ratio of 3.3 was modelled. The flow patterns and heat transfer in the enclosure were determined for Grashof Numbers in the range of 106 to 107 using a commercially available finite volume CFD solver.
It was found that the use of a single adiabatic baffle mounted vertically downwards from the apex, and extending the length of the enclosure, would alter the flow such that the heat transfer due to natural convection was reduced with respect to the length of the baffle.

Furthermore, it was observed that a series of convection cells, not previously reported in the literature, appeared to exist along the length of the enclosure. As such, it may be possible to derive additional benefit in reducing the heat transfer by adding lateral baffles in addition to the single longitudinal baffle modelled in this study.

Using input-output data in life cycle inventory analysis

The impacts on the environment from human activities are of increasing concern. The need to consider the reduction in energy consumption is of particular interest, especially in the construction and operation of buildings, which accounts for between 30 and 40% of Australia's national energy consumption. Much past and more recent emphasis has been placed on methods for reducing the energy consumed in the operation of buildings. With the energy embodied in these buildings having been shown to account for an equally large proportion of a building's life cycle energy consumption, there is a need to look at ways of reducing the embodied energy of buildings and related products. Life cycle assessment (LCA) is considered to be the most appropriate tool for assessing the life cycle energy consumption of buildings and their products. The life cycle inventory analysis (LCIA) step of a LCA, where an inventory of material and energy inputs is gathered, may currently suffer from several limitations, mainly concerned with the use of incomplete and unreliable data sources and LCIA methods. These traditional methods of LCIA include process-based and input-output-based LCIA. Process-based LCIA uses process specific data, whilst input-output-based LCIA uses data produced from an analysis of the flow of goods and services between sectors of the Australian economy, also known as input-output data. With the incompleteness and unreliability of these two respective methods in mind, hybrid LCIA methods have been developed to minimise the errors associated with traditional LCIA methods, combining both process and input-output data. Hybrid LCIA methods based on process data have shown to be incomplete. Hybrid LCIA methods based on input-output data involve substituting available process data into the input-output model minimising the errors associated with process-based hybrid LCIA methods. However, until now, this LCIA method had not been tested for its level of completeness and reliability. The aim of this study was to assess the reliability and completeness of hybrid life cycle inventory analysis, as applied to the Australian construction industry. A range of case studies were selected in order to apply the input-output-based hybrid LCIA method and evaluate the subsequent results as obtained from each case study. These case studies included buildings: two commercial office buildings, two residential buildings, a recreational building; and building related products: a solar hot water system, a building integrated photovoltaic system and a washing machine. The range of building types and products selected assisted in testing the input-output-based hybrid LCIA method for its applicability across a wide range of product types. The input-output-based hybrid LCIA method was applied to each of the selected case studies in order to obtain their respective embodied energy results. These results were then evaluated with the use of a number of evaluation methods. These evaluation methods included an analysis of the difference between the process-based and input-output-based hybrid LCIA results as an evaluation of the completeness of the process-based LCIA method. The second method of evaluation used was a comparison between equivalent process and input-output values used in the input-output-based hybrid LCIA method as a measure of reliability. It was found that the results from a typical process-based LCIA and process-based hybrid LCIA have a large gap when compared to input-output-based hybrid LCIA results (up to 80%). This gap has shown that the currently available quantity of process data in Australia is insufficient. The comparison between equivalent process-based and input-output-based LCIA values showed that the input-output data does not provide a reliable representation of the equivalent process values, for material energy intensities, material inputs and whole products. Therefore, the use of input-output data to account for inadequate or missing process data is not reliable. However, as there is currently no other method for filling the gaps in traditional process-based LCIA, and as input-output data is considered to be more complete than process data, and the errors may be somewhat lower, using input-output data to fill the gaps in traditional process-based LCIA appears to be better than not using any data at all. The input-output-based hybrid LCIA method evaluated in this study has shown to be the most sophisticated and complete currently available LCIA method for assessing the environmental impacts associated with buildings and building related products. This finding is significant as the construction and operation of buildings accounts for a large proportion of national energy consumption. The use of the input-output-based hybrid LCIA method for products other than those related to the Australian construction industry may be appropriate, especially if the material inputs of the product being assessed are similar to those typically used in the construction industry. The input-output-based hybrid LCIA method has been used to correct some of the errors and limitations associated with previous LCIA methods, without the introduction of any new errors. Improvements in current input-output models are also needed, particularly to account for the inclusion of capital equipment inputs (i.e. the energy required to manufacture the machinery and other equipment used in the production of building materials, products etc.). Although further improvements in the quantity of currently available process data are also needed, this study has shown that with the current available embodied energy data for LCIA, the input-output-based hybrid LCIA appears to provide the most reliable and complete method for use in assessing the environmental impacts of the Australian construction industry.

Green roof retrofit potential in the central business district

Purpose – The purpose of this paper is to illustrate the potential for green roof retrofit to commercial buildings in a city centre to property managers and other property professionals.

Design/methodology/approach – This paper addresses the research question: what is the potential of existing buildings in the CBD to accommodate a retrofitted green roof? Furthermore, it questions how many buildings are suitable for green roofs? The researchers compile a unique building database incorporating information about 536 commercial buidings and evaluate the potential suitability of each building to undergo a green roof retrofit. Assisted by other commercially available databases and software, the researchers are able to assess each roof based on criteria derived from an extensive literature review.

Findings – A relatively small proportion of roofs are found to be suitable, partly a result of local climate conditions and rainfall patterns, and the physical property stock. On a purely physical assessment, only a very small proportion of CBD stock is found to be suited. These buildings are most likely to be in low secondary locations, ungraded or B grade buildings, privately owned, concrete framed and not overshadowed by adjoining properties.

Practical implications – Property managers and other property professionals can now determine the potential of their portfolio stock for green roof retrofit based on the review of building attributes required for success adaptation in this paper. It possible that greater potential for green roof retrofit exists in the suburbs or regional towns where lower rise buildings may reduce the amount of overshadowing found in city centres. Follow-up research could focus on a comparison of regional and suburban developments.

Originality/value – This is the first study of its kind and has assessed such a large number of buildings for their suitability for green roof retrofit; the findings provide a reliable guide for policymakers regarding the potential number of city centre buildings which would be possible to retrofit. Such findings should influence policymaking and incentives to target effective sustainability policies with regards to existing buildings.