Kajavathani Panchalingam

Purpose: The Passivhaus Standard is internationally recognised for delivering high levels of energy efficiency, occupant comfort and indoor environmental quality. Despite these recognised benefits, its adoption in New Zealand remains limited, with concerns regarding construction costs, technical complexity, market readiness and policy support continuing to influence uptake. This study investigates multi-stakeholder perceptions of the cost-related drivers and barriers influencing Passivhaus adoption and identifies the key enablers for wider implementation. Design/methodology/approach: An exploratory quantitative research design was adopted using a questionnaire survey. A purposive sampling approach was employed to target stakeholders with experience in Passivhaus design, construction, certification, ownership and research. A total of 59 valid responses were collected and analysed using descriptive statistical techniques to examine perceptions of the economic benefits, barriers and adoption enablers. Findings: Operational energy cost savings are perceived as the most significant economic benefit associated with Passivhaus buildings. In contrast, perceptions of maintenance savings, property value enhancement and market premiums are comparatively less certain. High upfront construction costs emerged as the dominant barrier to adoption, followed by knowledge gaps, technical complexity, market limitations and insufficient policy support. In contrast, occupant-related concerns, including behavioural resistance and thermal comfort issues, were generally perceived as minor constraints. Stakeholders identified financial incentives, professional training, demonstration projects, public education initiatives and local supply-chain development as key enablers of wider adoption. Overall, the findings suggest that Passivhaus adoption in New Zealand is influenced not only by economic considerations but also by industry capability, market readiness, stakeholder awareness and policy support, indicating that wider adoption will require a combination of financial, technical, educational and policy-based measures. Originality/value: This study provides context-specific empirical evidence on the factors influencing Passivhaus adoption in New Zealand from a multi-stakeholder perspective. The findings contribute to understanding the economic, industry, market and policy factors shaping the uptake of high-performance housing and inform the development of a stakeholder-informed strategic framework to support wider Passivhaus adoption.

The escalating global primary energy demand highlights the need for sustainable practices, particularly in the New Zealand residential sector. Despite the proven benefits of well-designed, energy-efficient houses in reducing energy consumption and ecological footprints, misconceptions about high construction and operating costs hinder their wide adoption. Therefore, this study presents a detailed cost breakdown of an energy-efficient house in New Zealand, providing insights into cost distribution and offering a systematic approach to cost planning for future projects. A case study approach was employed, analysing an energy-efficient house with an estimated Homestar rating of 7-8 and a Gross Floor Area of 121 m². Data were obtained through document analysis, including drawings, specifications, quotations, manuals, and other building documents. A cost comparison was conducted based on the elemental breakdown provided by the New Zealand Institute of Quantity Surveyors and cost data from QV Costbuilder. Findings indicate that the total construction cost of the energy-efficient house, approximately NZD 3,700 per m², exceeds the average cost of similar single-storey houses in different New Zealand cities. According to the cost distribution analysis, the main contractor accounted for 68% of the total costs, with materials comprising 44%, labour at 16%, and management costs at 8%. Based on elemental analysis, internal finishing, external fabric, and building structure contributed 29%, 24%, and 19%, respectively. The study is limited by procurement type, building shape, and site-specific conditions. However, its findings provide valuable insights to inform decision-making and enhance the feasibility of energy-efficient houses in New Zealand.

Passivhaus (PH) has gained global recognition for its energy-efficient features despite a 5% to 10% higher construction cost than traditional houses, especially within European countries. However, its adoption and popularity have not met the same fate in other countries like New Zealand. The higher upfront cost has been critical to the slow adoption of the PH movement in New Zealand. This study aimed to demystify the mist around the cost of PHs with a focus on the effects of drivers and barriers on their life cycle costs (LCCs). As such, a systematic literature review was conducted to provide a comprehensive understanding of the cost implications associated with PH. Using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) review method, we examined 71 past studies on PHs from 2005 to 2023. We found that the drivers of PHs include reduced heating demand, increased thermal comfort, and indoor air quality (IAQ). Research showed that the rising market for PHs is fueled by climate change, environmental awareness, innovative materials and technologies, individual commitment, improved regulations, pilot studies, research efforts, and governmental funding and initiatives. However, PHs face significant challenges such as increased complexity, advanced technology, higher initial investments compared to conventional and low-energy houses, national requirements, overheating, difficulties in affording the technologies, and a lack of options in the market. Despite the wealth of research on the economic aspects of PH, there is a lack of in-depth studies exploring the LCC of PHs focusing on cost commitments and benefits. Such studies are essential for assessing and optimising the cost-effectiveness of PH, considering different climates and regions, and comparing them with other low energy standards. The findings of our review provide a crucial focus for PH stakeholders in assessing the long-term financial viability of PH projects, thereby improving decision-making and facilitating effective planning for sustainable and cost-effective housing.

High-rise (HR) development projects face significant risks and time constraints. The majority of owners seek the projects to be completed early. Early identification of the factors affecting CTP (Construction Time Performance) would allow to reduce or eliminate time overruns. The contractor plays a significant role in CTP. CQSs (Contractor Quantity Surveyors) have also been receiving increasing attention concerning CTP. The roles performed by CQSs can be utilized to control the factors affecting CTP. Therefore, this study focuses on the factors affecting CTP in HR buildings and the role of the CQS (Contractor Quantity Surveyor) in CTP. The study used a qualitative approach. Semi-structured interviews selected through purposive sampling were used to gather the required information. The data were manually analyzed using content analysis. Fifty-four factors were identified and classified under six categories. A new additional factor was identified. Interviewees endorsed 49 factors that have a substantial impact on CTP. Seventeen roles of CQSs were identified. The identified 17 roles can influence thirty-three CTP-related factors. The study intends to increase awareness of enhancing CTP related to HR building projects.

This paper describes an empirical experiment of Internet of Things (IoT)’s integration in the Post-Occupancy Evaluation (POE) process. The experiment aimed to trial a novel IoT approach to enabling building user responsiveness to prevalent IEQ for individualised comfort. The purpose is to provide a system that mitigates a common issue of centralised air conditioning that limits occupants’ control over their immediate environment. To achieve this, an IoT platform was developed with smart IEQ monitoring sensors and wearable devices and trialled with PhD researchers in a shared university workspace. The findings provided empirical evidence of IoT’s enhanced benefits to improving user control over their individual comfort and enabling positive energy behaviour in buildings. Specifically, the IoT system provided real-time insight into CO₂ concentration data while enabling responsive occupant interaction with their immediate environment and at-the-moment mitigation actions. Outputs of the experiment showed that the perceptions of participants about the stuffiness of the air, productivity, and healthy environment were significantly better after taking the mitigation action compared to before. Also, we found a significant relationship between measured CO₂ concentration readings and perceived air stuffiness (p = 0.004) and productivity (p = 0.006) and a non-significant relationship between CO₂ concentration readings and perceived healthy environment (p = 0.058). Interestingly, we observed that irrespective of the similarities in recorded CO₂ concentration readings being within acceptable ranges (632–712 ppm), the perception of air stuffiness significantly differed (p = 0.018) before and after the mitigation actions. The effectiveness of the developed IoT platform was evidenced as most of the participants found the process very easy to participate in with little interruptions to their work as little time was consumed. The results are useful in modifying approaches to building occupant comfort and energy behaviour in commercial and residential settings.

The current socioeconomic demand requires adequate engineering performance and environmentally friendly materials from the perspective of sustainable development. The scarcity of conventional natural resources and the severe environmental consequences of extraction have prompted research into alternative materials and resources for use in the road industry. Based on the findings of the existing studies, this research aims to explore the suitability of alternative materials for road construction projects towards sustainability in Sri Lanka. A quantitative research strategy was employed in the current study, and the questionnaire was distributed among 44 professionals involved in different types of road projects. The collected data were analysed by using Relative Important Index (RII). 84% of respondents considered alternative sustainable construction materials are highly suitable for the construction of road elements. Bituminous materials, natural soil, crushed rock and cement concrete are mostly commonly traditional materials. Construction and demolition waste (C&D), fly ash, plastic waste, and waste rubber tires were selected as the best materials for base construction, cement kiln dust waste, fly ash, glass waste, and waste rubber for sub-base and C&D waste and glass waste for sub-grade construction. Alternative sustainable materials can solve the waste disposal issue, scarcity of natural materials, and cost savings. Thus, this study presents a collective listing of the most viable alternative materials already in use by the global industry, with the goal of establishing a noble notion for better incorporation of alternative sustainable materials into road construction in Sri Lanka.