Australian Building Research Articles

The Evolving Nature (or Not) of Sustainability Communications in New Home Building in Australia

Research has demonstrated that sustainable homes can help mitigate the impact of climate change and assist with meeting international climate targets. However, market implementation has been slow due to limited regulatory regimes and poor engagement by home builders across Australia. In Australia, homes are commonly built by ‘volume home builders’ (VHBs), who are defined as home builders who build large quantities of homes, generally from a standardised set of plans and formats. The Housing Institute of Australia (HIA) ranks the largest volume home builders annually in their top 100 home builders report. To evaluate the VHBs’ approach to communicating sustainability in their home products, this study used content analysis techniques to investigate their use of online communication channels (websites, blogs and social media accounts). This study examined 23 New South Wales VHBs in 2020 and 2022 and compared them to a study of Australia’s top 100 VHBs in 2016. The findings demonstrated a significant increase in the level of sustainability communications in their online channels between 2016 and 2020 but showed a decrease between 2020 and 2022. Overall, the level of detail, the type of information and the educational quality improved from 2016 to 2022. However, only two VHBs provided a high level of sustainability information. The most recent results illustrated that VHBs have moved away from having sustainability links and terminology on their websites compared to the 2020 baseline. This study demonstrated that leading Australian VHBs have an enormous opportunity to improve their sustainability messaging and suggested recommendations for enhancing communication capabilities and providing more meaningful sustainability information.

Utilisation of certification schemes for recycled products in the Australian building and construction sector

AbstractRecycled product certification (RPC) schemes may prove useful to ensure the desired quality and gain buyer confidence in purchasing products with recycled content (PwRC). RPCs are relatively new to the sector and have not been widely adopted. Hence, this study aims to investigate the implementation of RPC in construction projects using a multiple‐case study approach. The analysis reveals that a large proportion of respondents were unaware of these schemes. The study finds that while a majority favoured RPC application, there were significant variations in responses among stakeholder groups. Moreover, the study identifies six advantages and seven significant barriers associated with the use of RPC in the sector. This study recommends leveraging education and supportive regulation for the effective implementation of RPC. In particular, the policymakers who intend to embed RPC in procurement policies for purchasing PwRC can learn about the identified loopholes and strategies and address them accordingly.

New Zealand Architects and Australia’s Federation Architecture

ABSTRACT In 1887, Thomas Searell (1855-1938), Percival Selwyn Richards(1865-1952) and William Allen Tombs (1866-1928), architects trained in Christchurch, New Zealand, migrated to Melbourne, Victoria. A few years later they spread out to regional Victoria and Tasmania consolidating practices in the early 1900s in Ballarat (Richards), Geelong (Tombs), Hobart and Launceston (Searell). In those locations they became prominent practitioners, proficient in design discourses at the turn of the twentieth century which are now described in Australia as “Federation” architecture – a term that aligns design with the political realisation of Australia as a nation in1901. Yet the maintenance of personal connections and commonalities in their Australian buildings might be traced to the New Zealand architectural practice of Frederick Strouts who articled Searell in the 1870s and Richards in the early 1880s, and whose one-time assistant, Thomas Stoddart Lambert (1842-1917), articled Tombs in the early 1880s. At stake in this article, then, is the role of a larger region in late nineteenth and early twentieth-century Australian architecture. As such, the work of these regional NewZealand/Australian architects serve as a reminder of the limitations of nationalist frameworks that define our region’s architectural histories captured in stylistic terminology such as “Federation.”

Challenges for implementing biophilic strategies in Australian building design

Although biophilic design, particularly, direct nature integration (DNI) strategies like green roofs and green walls are associated with multiple benefits including building occupants’ well-being and carbon sequestration, their adoption in building design is limited in some developed countries like Australia. Architects and building sustainability consultants significantly influence design decisions; however, research focused on exploring DNI adoption barriers from their perspective is limited. Therefore, this research aimed to investigate the challenges limiting adoption of DNI strategies in Australia through the lens of innovation adoption theories. Semi-structured interviews with 24 architects and sustainability consultants focused on identifying barriers stemming from “organisation”, “building client”, “designer”, “innovation”, and “socio-political influencers”. Like in previous studies, “budget constraints” and “maintenance burden” were identified as key barriers in this research, thus, affirming their persisting negative impact on DNI adoption. However, the innovation adoption framework led to identifying new barriers like “builder influence” (socio-political influencers), “employment circumstances” (designer), and “business constraints” (organisation). The new barriers discovered in this research may be relevant to other countries; however, further studies are needed to identify dimensions relevant to other contexts. These studies will benefit from the research framework developed in this research.

Clustering based analysis of residential duck curve mitigation through solar pre-cooling: A case study of Australian housing stock

A clustering based analysis of solar pre-cooling for around 450 Australian homes equipped with rooftop Photovoltaics (PV) and Air Conditioning (AC) is presented. By simulating the thermal performance of nine typical Australian building types for each household, a virtual housing stock is created. These modeled building types include 2-, 6-, and 8-star homes, and for each star rating, three different construction weights (i.e., light, medium, and heavy). The analysis finds that there are four clusters of AC excluded net demand profiles that usefully characterize the household dataset, out of which three clusters cover around 97% of households. Homes that fall within these three clusters offer ‘flattening’ demand profile improvement, which is mainly achieved by minimum demand mitigation, with a maximum of up to 4 kW across the households. Analyzing the limiting factors shows that thermal comfort requirements of households do not particularly impact on solar pre-cooling which is, instead, mainly limited by the house's AC size and typical surplus PV generation. Finally, the cost savings resulting from implementing solar pre-cooling during the three months of summer can be as high as around A$185 with a zero Feed-in Tariff (FiT) and typical Australian residential prices.

Framework for measuring resilience of safety management systems in Australian building repair and maintenance companies

Introduction: The complex and dynamic nature of building repair and maintenance (R&M) work tends to create safety risks for workers. Resilience engineering approach is identified as a complementary to conventional safety management techniques. Resilience of safety management systems is characterized by the capabilities to recover from, respond during, and prepare for unexpected situations. This research aims to conceptualize resilience of safety management systems in the building repair and maintenance context by introducing resilience engineering principles into the safety management system concept. Method: Data were collected from 145 professionals in building repair and maintenance companies in Australia. The structural equation modeling technique was utilized to analyze the collected data. Results: The results confirmed three dimensions (i.e., people resilience, place resilience, and system resilience) with 32 measurement items for assessing resilience of safety management systems. The results revealed that safety performance of building R&M companies was significantly affected by the interactions between people resilience and place resilience and the interactions between place resilience and system resilience. Conclusions: Theoretically, this study contributes to the safety management knowledge by theoretically and empirically supporting the development of concept, definition, and purpose of resilience for safety management systems. Practical Applications: Practically, this research proposes a framework for assessing the level of resilience of safety management systems that is characterized by employees’ capabilities, supportiveness of workplace, and supportiveness of management to recover from safety incidents, react during unexpected situations, and prepare for preventative actions before occurrence of undesirable events.

Building Energy Performance Modeling through Regression Analysis: A Case of Tyree Energy Technologies Building at UNSW Sydney

Addressing clients’ demands, designers have become increasingly concerned about the operation phases of buildings and, more specifically, energy consumption. This issue has become more prominent as people realize that the Earth’s resources are limited and depleted, and buildings are major energy consumers. Building Information Modelling (BIM) has gained popularity in recent years and is now widely used by architects, engineers, and construction teams to collaborate and provide a comprehensive design that follows a sustainable strategy. The objective of this research is to examine how building variables are linked to energy consumption in various building shapes, achieved by building prototypes. The accuracy of the regression models is evaluated by undergoing a validation process. Consequently, this study created building information models of selected education facility office rooms and used Autodesk Insight 360 and Green Building Studio (GBS) to perform energy simulations. A 6 Green Star education building in Australia is chosen as the case study of this paper. Thirteen variables related to building internal design were examined, and five were found to endure a substantial effect on building energy consumption. The study also looked at the window-to-wall ratio (WWR), which was analyzed by multi-linear regression; however, the results showed that the model did not fit well, and the error obtained during the validation process ranged from 1.0% to 26.0%, which is unacceptable for this research. These findings highlight some limitations in using BIM tools and linear regression methods and discuss some potential improvements that can be achieved in future studies.

Processing and Configuring Smart and Sustainable Building Management Practices in a University Building in Australia

Australia’s building energy use accounts for a significant portion of the country’s energy consumption and greenhouse gas emissions. Buildings consume energy for a variety of purposes, including space heating, cooling, lighting, and powering electronics. Smart and sustainable building management practices allow buildings to be managed and operated more efficiently and sustainably. This study investigated the energy consumption and building management performance of a university building in Sydney, Australia. The experiment was performed by monitoring occupant comfort and building performance feedback with a push-pull mobile phone application and portable sensor technologies. The results showed that several factors influenced the occupants’ environmental comfort level, including temperature, lighting, noise, air quality, air movement, and relative humidity. Nevertheless, the ambient office temperature has a significantly higher impact on occupants’ comfort level. Results also showed that the local temperature experienced and preferred by individual occupants may vary, even under identical thermal conditions. The outcomes also confirmed strong correlations between the comfort and concentration levels (r(231) = 0.61, p = 0) and between the comfort and productivity levels (r(231) = 0.62, p = 0). Temporal analysis also revealed lower comfort levels between 13h00 and 16h00 and higher comfort levels between 10h00 and 12h00 and 17h00 and 19h00. The findings of this research indicated that ≤4% of total annual building energy consumption costs may be saved by more effectively and efficiently managing office thermostat control. More accurate and zone-based energy analysis could also reveal higher energy savings through smart occupant feedback-oriented thermostat and lighting control in commercial and office buildings.

Assessing the “sufficient ventilation” requirement for Austrian buildings: development of a Monte Carlo based spreadsheet calculation to estimate airing intervals and mould risk in window ventilated buildings

In Austria the lack of guidelines or standards has caused many discussions and disputes on the question if “sufficient ventilation” can be ensured with window airing only, in particular in newly constructed, airtight residential buildings. This work presents the development of a calculation method aiming to provide a simple-to-use tool to estimate the risk of mould growth and the window airing interval required to ensure good indoor air quality assuming a range of different boundary conditions and occupant behaviours. The method implements a Monte Carlo approach calculating 1000 single zone mass balances for carbon dioxide (on a room level) and water vapor (on a housing level). Air infiltration through the building envelope is accounted using the so-called LBL-model. The time interval between window airing required to comply with CO2 limit value is estimated by calculating the time evolution of the CO2 concentration for 1000 different parameter combinations. The mould risk is estimated by a 1000-fold calculation of the daily averaged indoor air humidity and the resulting water activity on critical wall surfaces. The results are displayed as probability distributions providing information on the risk that the queried situation can or cannot ensure “sufficient ventilation”. Exemplary calculations for bedrooms of new multifamily buildings estimate that intervals between window airing events (to keep time-averaged CO2-concentration below 1000 ppm), will vary between 23 and 190 minutes (representing the 5th and the 95th percentile). This is clearly below an acceptable intervention interval for bedrooms. For living rooms, the assessment shows a strong sensitivity on the “accessible” air volume. The humidity assessment for this type of housing suggests that mould growth could occur in about 17% of the cases even though air exchange corresponding to two airing events per day were assumed. An additional outdoor air exchange of up to 40 m³/h would be required to reduce the mould risk fraction to <1%, suggesting the need for mechanical ventilation concepts in residential housing to enable healthy indoor environment independently of occupant behaviour.

Roof integrated photovoltaic for electric vehicle charging towards net zero residential buildings in Australia

The residential building sector & transportation sector has received significant attention in recent years due to carbon emissions affecting the livelihoods of humans. Electric vehicles (EVs) are poised to play a vital role in reducing dependency on non-renewable fuels and the transportation sector's environmental implications. Building integrated Photovoltaics (BIPV), on the other hand, will be able to cut down the energy requirements and contribute to building sustainability. This paper evaluates the energy, economic, and environmental performances of BIPV with EV charging system systems for a building in Canberra, Australia. BIPV with EV charging can assist in fulfilling building energy needs, charging electric vehicles, and reducing grid reliance. Different load scenarios were studied to optimize system size. Different panel layouts with orientation have been studied for the 5.0kWp BIPV system, each module rating 355kWp. The annual energy output of the BIPV system was found to vary between 8.56 MWh for layout one and 7.08MWh for layout 3. It was found that the payback back of the proposed BIPV system is 4.46 years, LCOE of 0.074AUD/kWh and EV charging cost of 0.95AUD/100 km. The BIPV with EV charging system could save approximately 160,198 kgCO2e in GHG emissions over its lifespan.

Solar Hot Water Systems Using Latent Heat Thermal Energy Storage: Perspectives and Challenges

Domestic water heating accounts for 15% to 27% of the total energy consumption in buildings in Australia. Over the past two decades, the latent heat thermal energy storage (LHTES) system has been widely investigated as a way to reduce fossil fuel consumption and increase the share of renewable energy in solar water heating. However, the research has concentrated on the geometric optimisation of the LHTES heat exchanger for the past few years, and this might not be sufficient for commercialisation. Moreover, recent review papers mainly discussed the development of a particular heat-transfer improvement technique. This paper presents perspectives on various solar hot water systems using LHTES to shift focus to on-demand performance studies, as well as structure optimisation studies for faster commercialisation. Future challenges are also discussed. Since the topic is an active area of research, this paper focuses on references that showcase the overall performance of LHTES-assisted solar hot water systems and cannot include all published work in the discussion. This perspective paper provides directional insights to researchers for developing an energy-efficient solar hot water system using LHTES.

The influence of earthquake characteristics on the seismic performance of reinforced concrete buildings in Australia with varying heights

In Australia, most of the existing buildings were designed before the release of the Australian standard for earthquake actions in 2007. Therefore, many existing buildings in Australia lack adequate seismic design, and their seismic performance must be assessed. The recent earthquake that struck Mansfield, Victoria near Melbourne elevated the need to produce fragility curves for existing reinforced concrete (RC) buildings in Australia. Fragility curves are frequently utilized to assess buildings’ seismic performance and it is defined as the demand probability surpassing capacity at a given intensity level. Numerous factors can influence the results of the fragility assessment of RC buildings. Among the most important factors that can affect the performance-based seismic assessment of buildings are the building height and the characteristics of the earthquake. Despite this, very few studies accounted for the earthquake characteristics and the influence of height on the vulnerability of buildings in Australia. Consequently, the combined effect of building height and the characteristics of the earthquake were investigated in this study. This was achieved through numerical modeling and time-history analyses of three typical two-, four-, and nine-story RC frame buildings in Australia. Moreover, these buildings were subjected to three different types of ground motions which were: short- and long-duration, and near-fault earthquakes. Fragility analysis was then conducted for the three buildings under all the selected earthquake suites. It was noted from the median values of the fragility curves that the four-story and the nine-story RC buildings were 17% and 18% more susceptible to damage in comparison with the two-story building under short-duration earthquakes. Moreover, it was also noted that the median value of the vulnerability increased by 33%, 40%, and 50% for the two-, four-, and nine-story buildings, sequentially, when subjected to near-fault compared to short-duration earthquakes.

The Ignition Frequency of Structural Fires in Australia from 2012 to 2019

Appropriate estimates of ignition frequency derived from fire statistics are crucial for quantifying fire risks, given that ignition frequency underpins all probabilistic fire risk assessments for buildings. Rahikainen et al. (Fire Technol 2004; 40:335–53) utilized the generalized Barrois model to evaluate ignition frequencies for different buildings in Finland. The Barrois model provides a good prediction of the trend of the ignition frequency; however, it can underestimate the ignition frequency depending on the building type. In this study, an analysis of the Australian fire statistical data from 2012 to 2019 was performed and compared with studies from Finland. A new coefficient is proposed to improve the Barrois model for a better fit for buildings in Australia. Several categories, such as hotels and hospitals, which were absent in previous studies, have been included as separate categories in this study. Office and retail spaces in Finland have an ignition frequency one order of magnitude lower than in Australia. On the other hand, other buildings (retail and apartments in particular) are much more prone to fire ignition in Australia than in Finland. The improved generalized Barrois model based on the Australian fire statistical data will be useful for determining ignition frequency for risk quantification in the Australian context.

Extending urban energy transitions to the mid-tier: Insights into energy efficiency from the management of HVAC maintenance in ‘mid-tier’ office buildings

Older, smaller and poorer quality commercial buildings (the ‘mid-tier’) make up much of the commercial building stock and are crucial for urban energy transitions. Action must extend beyond new commercial buildings and high-end building retrofit projects to realise deep decarbonisation of the built environment. Mid-tier buildings offer substantial opportunity for energy retrofits, though the sector lags behind premium office buildings. Comparatively, different ownership structures, tenant profiles, and facilities management regimes challenge the value-proposition for energy transition, and little is known about how to leverage energy performance improvements in this crucial sector. Focussing on the management of heating, ventilation and air-conditioning (HVAC) systems as an entry point for improvement, this paper presents empirical evidence from the largest survey conducted with Australian HVAC contractors, facility managers, and system engineers to date. The results explicate the realities of managing energy in mid-tier office buildings in Australia as a socio-technical undertaking. Our analysis identifies limits and opportunities for shaping energy efficiency of HVAC maintenance, focussed on issues pertaining to workforce, building and systems, and maintenance practices. Further, we draw out policy imperatives needed to address hurdles created by multiple market failures that complicate energy transition in mid-tier buildings.

Is 24.9 °C Too Hot to Think? A Call to Raise Temperature Setpoints in Australian Offices

The current +−0.5 PMV (Predicted Mean Vote) targets adopted by NABERS (National Australian Built Environment Rating System) is the practical range deemed acceptable for 90% acceptability for commercial buildings in Australia, however thermal comfort satisfaction scores measured in office buildings still show high percentages of dissatisfied occupants. This paper aims to demonstrate the potential of curbing energy consumption from commercial buildings in Australia by increasing summer temperature set-points. A 10-year NABERS dataset, along with objective and subjective thermal comfort and air quality data from NABERS-certified offices are investigated in this study. Furthermore, different simulation scenarios are tested to investigate the discomfort hours and energy consumption for various summer temperature setpoints. Result analysis shows that occupants’ satisfaction in NABERS-certified buildings was not within the 90% satisfaction, with being too cold/hot as the main source of dissatisfaction. Objective measurements also showed temperature was out of recommended range for several datapoints. Simulation results indicate that, within the average range of 21–24.9 °C, there is not a significant difference in discomfort hours that could drive the selection of one temperature set-point over the other. Challenging the current practices, results suggest that a cooling set point temperature on the upper limit of the range indicated by the Australian standard AS 1837–1976 may minimize the energy consumption without significantly increasing discomfort, or even increasing the perceived satisfaction with the indoor environment.

Analysis of extreme wind gusts using a high-resolution Australian Regional Reanalysis

The characterisation of extreme wind gust speeds has historically relied on data from observations, while numerically modelling these events is limited due to their rarity and localised nature. However, the ongoing increase in computational power now allows extreme events to be characterised in fine-scale numerical data. Extreme gust events are examined using 24 years of 1.5 km horizontal grid reanalysis data for eastern Australia, and compared to those based on 1-minute data from station observations. We estimate return values over long periods using the generalised Pareto distribution (GPD) peaks-over-threshold approach. An automated algorithm that selects an optimal threshold at each grid point is outlined and gives similar results to an approach based on pre-fixing the shape factor value similar to what is applied in Australian building design standards. We also present a decision tree model that skillfully distinguishes between convective (i.e., thunderstorm) and synoptic (e.g., frontal system and cyclone) gust events using only hourly reanalysis data. The reanalysis shows high synoptic gust intensities and frequencies along the coast, consistent with station observations, and that synoptic-type extreme gusts are enhanced by topography (higher occurrence frequencies in mountain areas) while convective-type events are less affected. The reanalysis systematically overestimates parameterised gust activity, while compensating for this at many locations by underestimating the resolved wind speed, thus often producing gusts close to observed. With the proviso that these issues are considered, we find that the information on wind gusts provided by reanalysis data may be quite useful especially in regions with low observational network coverage.

Impact of variable electricity price on heat pump operated buildings.

Background:Residential buildings with heat pumps show promising possibilities for demand-side management. The operation optimization of such heating systems can lead to cost reduction and, at the same time, change electricity consumption patterns, which is especially prevalent in the case of a variable price signal. In this work, we deal with the following question: How does the volatility of a variable retail electricity price change the energy consumption of buildings with a smart energy management system? Methods:In this context, we take Austria as an example and aggregate the findings of individual households to the national stock of single-family houses. This is done by simulating and optimzing heating operation in single representative buildings. The aggregation is done based on national building information statistics. Results:This part of the Austrian building stock could shift 19.7 GWh of electricity per year through thermal inertia using a real-time electricity price from 2021. We show the future potential under the assumption of three electricity price trends for 2030, representing different decarbonisation ambition levels. The trends show that higher decarbonisation levels which lead to higher electricity prices increase the incentive to shift electric loads. Conclusions:Real time pricing turns out to be an effective incentive for buildings to shift electric loads by pre-heating the building mass. However, cost savings for individuals are relatively low which is why additional monetary incentives are needed to tap into that potential. Increased daily peak-to-peak demand from these buildings has to put into perspective to the overall grid load.

Delivering a net zero carbon built environment – Targets and Pathways

Carbon neutrality is expected to address climate change challenges, and its achievement requires the collective efforts of various industries and sectors. The building and construction sector is a big energy consumer and greenhouse gas emitter, providing numerous opportunities for carbon neutrality. This indicates a need for a net zero carbon built environment, although the targets and pathways to it are still unclear. The paper, therefore, aims to address this research gap by reviewing the existing definition of net zero carbon and the targets set by international institutions (e.g., GABC, WorldGBC, RIBA, LETI, and AIA). The paper also defines the principles behind setting the decarbonisation targets, and presents the pathways tailored to the Australian building and construction sector. Overall, this paper is of importance in demonstrating a methodological framework for determining the net zero operational and embodied carbon targets and the associated pathways for decarbonising the built environment. The method is expected to be suitable for many other nations.

Investigating the energy use in an Australian building: A case study of a west-facing apartment in Sydney

This study presents the simulation of retrofitting measures in a residential apartment located in Sydney based on energy consumption, building characteristics, and climatic conditions through energy audits. From the results, an upgrade to a casement aluminum framed double glazing window with a thermal conductance (U-Value) of 2.3 W/m2/oC, having an initial cost of $6,570, will save 41.2 % and 21 % of the energy used for heating and cooling equipment with a simple payback of 6.3 years and fuel cost savings of $1,046. In addition, 787kWh of electricity saved from white goods by investing $1,050 has a payback of 2.2 years and fuel cost savings of $472. Finally, the building will save 2.7 tons of GHG emissions, equivalent to three people reducing energy use by 20 % in Australia. The research is vital because retrofitting multi-residential buildings in Australia has not been fully explored, leaving 7.8 million existing buildings that are not energy efficient.

Global Policy Review on Embodied Flows: Recommendations for Australian Construction Sector

There has been a call for the construction industry to become more energy efficient in its planning and activities, to reduce greenhouse gas emissions to help combat climate change. The Australian Building Codes Board has implemented ‘Energy Efficiency’ standards through the National Construction Codes to direct the industry towards net zero emissions goals. However, the Board has maintained a focus on operational flows considerations despite this only being a part of the total expenditure in a building lifecycle. Embodied flows, the energy output, and emissions from harvesting, manufacturing, transporting, and manufacturing materials for a building have not been included as a part of the current standards despite their growing share in the outputs of construction. A qualitative document analysis using data from academic articles and industry publications was performed to identify the context in embodied policy development. Findings reveal an abundance of different legislations and initiatives globally, recommending techniques that may effectively achieve embodied flow reductions. The results highlighted that Australia needs to capitalize on the potential reductions in overall energy and emissions from construction. Other regions have provided a strategic and legislative basis for the industry to emulate.