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• Construction Waste Management (CWM) credits are least sought out in green buildings. • To obtain CWM credits, one needs to pay a higher cost ranging from 0.4% to 6% • The number of credits and weightage allocated for the CWM related credits are lower. This research was motivated by the intriguing phenomena across several economies that green building clients/developers are observably lukewarm in pursuing construction waste management (CWM). Recent studies, most of them in a qualitative nature, reported that to obtain CWM-related credits is "costlier" than obtaining credits from other green building aspects such as sites, lighting, and so on. Yet, there is a clear lack of empirical analysis of such cost implications with a view to providing convincing explanation to the phenomena. This research aims to identify the cost implications of achieving CWM-related credits as stipulated in green building rating tools by focusing in Hong Kong. The costs for using materials required for green certification were calculated and compared against conventional materials by introducing a life cycle perspective. It is discovered that to obtain the CWM-related credits, one needs to pay a higher cost ranging from 0.4% to 6%. [ABSTRACT FROM AUTHOR]

Cement is one of the widely used materials in construction. Due to the adverse impacts towards the environment from cement manufacturing, green building rating tools always give a significant consideration towards concrete usage in green buildings. Irrespective of its significance in green buildings, there is a clear lack of research on life-cycle cost (LCC) impact of using supplementary cementitious materials (SCMs) in cement as required by green building rating tools. Therefore, this research analyses the life cycle costs of concrete using SCMs in obtaining concrete credits according to Green Star rating system in Australia. This research used fly ash, slag and silica fume as SCM for concrete. The SCM replacement percentage in concrete ranges from 10% to 60% as higher than 60% substitution is impractical. This research calculated LCC for each replacement percentage and specific building elements in different strength categories. LCC of concrete decreases with higher SCM replacement percentages. Further, there are only slight differences in LCC when comparing the three SCMs. In LCC, the contribution from the initial material cost is approximately 85%–87%, and in an exceptional situation such as in columns, this lowers to 66%. In larger columns, the cost of demolition is greater than that of the initial cost whereas it contributed to 61%–68% of the LCC. [ABSTRACT FROM AUTHOR]

The construction industry has a significant contribution towards numerous adverse environmental impacts. Therefore, green building concept has gained wide recognition. In line with this, numerous international green building rating tools have been developed providing a yardstick for measuring green building performance. These rating tools have different credit criteria for evaluating the green building performance. According to the existing literature, there are many researches comparing different green building rating tools on specific credit criteria such as “Energy”. However, there is a clear lack of research on establishing a baseline to develop new green building rating tools and to evaluate existing green building rating tools. Therefore, this research aims to establish key credit criteria based on an extensive literature study and evaluate these criteria based on widely used eight green building rating tools. The comparison analysis is based on a quantitative measure, namely, a normalised score, which is obtained through allocating credit points of selected green building rating tools to the established key credit criteria. The comparison result is presented with radar diagrams and bar charts. This research established seven key credit criteria for these rating tools which are namely (1) Site, (2) Energy, (3) Water, (4) Indoor Environment Quality (IEQ), (5) Material, (6) Waste and pollution, and (7) Management. It is found that ‘Energy’ criterion is the most widely considered key credit criteria and then followed by ‘IEQ’ and ‘Water’ criteria. Apart from that, credit criteria such as ‘Triple bottom line reporting’, ‘Education and awareness’, ‘Economic aspects relating to various costs’, ‘Sustainable designing and planning’ and ‘Stakeholder relations’ are identified as possible credit criteria which can be included in developing the rating tools in future. These key credit criteria can be adopted as a baseline to develop new green building rating tools, and it provides fruitful results to develop the existing tools further. [ABSTRACT FROM AUTHOR]

Renovation of residential buildings is very common in China. Parallel to the renovations, a significant of renovation waste is generated, majority of which end up in landfills posing significant environmental and health hazards. Approximately up to 7.5 million tons of renovation waste is generated annually in China, yet, there is a clear lack of research on renovation waste management. A framework to manage the renovation waste is highly desired. Hence, this research aims to develop a conceptual framework for renovation waste management based on the renovation waste generation rates (RWGRs). Initially, the renovation waste is classified into the five phases of renovation waste generation. The five phases are, 'layout transformation', 'installation engineering', 'mason engineering', 'carpentry engineering' and 'paint engineering'. Once the conceptual framework is developed, it was necessary to quantify the RWGRs. Renovation waste estimation was done on-site by sorting and weighing. It is found that the renovation waste is mainly contributed by concrete blocks, bricks, timber and ceramic tiles. The results obtained from the research study reports that the RWGRs vary between 15.65 kg/m2 and 25.98 kg/m2. The highest RWGRs are reported in 'layout transformation' phase. The 'paint engineering' phase generates a comparatively small amount, yet toxic waste. The research provides significant insights to developers, project managers, site managers and all the professional working with renovation waste in developing a waste management framework based on the RWGRs. [ABSTRACT FROM AUTHOR]

Solar electricity that is produced from photovoltaic solar systems has the potential to deliver clean sustainable energy. Positive steps are being undertaken to minimise greenhouse gas emissions in Australia and photovoltaic solar systems are contributing towards sustainability. The current amount of installed photovoltaic solar systems cannot address the global warming issues in whole, however renewable energy production is contributing towards minimising carbon emissions. One of the main concerns for the residential householders is the economic issue on the use of photovoltaic solar systems. This paper examines life cycle cost effectiveness in using photovoltaic solar systems with capacities ranging from 1.5 kW to 5 kW in relation to the number of occupants and consumption for residential dwellings over a 25-year period. Eight major cities in Australia, including Sydney, Canberra, Melbourne, Brisbane, Hobart, Adelaide, Darwin and Perth, are investigated. Life cycle cost comparisons among different types of electricity grid connected systems, including a gross-feed-in-tariff (GFIT) scheme, a net-feed-in-tariff (NFIT) scheme and a buy-back scheme, are also explored. It is found that all major cities can receive life cycle cost saving in installing photovoltaic solar systems in their residential dwellings. The life cycle cost saving is between $273 and $53,021 and the percentage of cost saving is between 0.35% and 123.83% in a 15-year period. It appears that the GFIT and NFIT schemes offer better benefits than the buy-back scheme in installing photovoltaic solar systems. It is also found that the higher the capacity of the photovoltaic solar systems, the higher the life cycle cost saving can be received. This paper contributes to prove the cost effectiveness of using photovoltaic solar systems with the example from Australian residential dwellings. [ABSTRACT FROM AUTHOR]

Green buildings are gaining popularity in Australia with the applications of Green Star rating scheme. However, the credit for using timber materials in the rating scheme, while timber being a significantly used material in the fast growing residential construction industry, does not adequately guide designers and builders on the selection of the best timber types for residential applications from the life cycle perspective. This research presents the analysis on the life cycle cost of timber materials in their various applications for residential buildings in Australia and thereby provides guidance on how to best meet the requirement set out in the timber credit in the Green Start rating scheme. Structured interviews were used to collect the data on the cost of timber materials in their lifetime from builders, tradesmen and other residential construction professionals. Three sets of cost information were received under each application, for the individual timber species against three conditions (low, medium and extreme weather) with reference to residential buildings. Based on life cycle cost analysis results, the most suitable timbers for different applications are recommended. [ABSTRACT FROM AUTHOR]