Status and barriers to circular bio-based building material adoption in developed economies: The case of Flanders, Belgium.

Circular bio-based building materials (CBBMs) provide a potential solution to reduce the climate impacts of buildings and offer opportunities to transition the construction industry to a circular model. Promoting the use of these materials can also bring economic, environmental, and social benefits from valorising biowaste and by-products from other sectors. Despite their potential, CBBMs have not received sufficient attention globally, and their adoption is hindered by various barriers. However, it is unclear what the CBBMs' use status is, what adoption barriers exist, how these barriers interact, and what should be done to address them. This study addresses these knowledge gaps through a systematic study using mixed methods to investigate the adoption status and barriers to these materials in developed economies by using a specific case analysis in Flanders. The data analysis results show that hemp-based, cork-based, and straw-based materials are the most used, while the market for CBBMs is very limited in the region. Twenty-three potential adoption barriers were identified and selected from the existing literature, then ranked based on their mean scores. The t-test analysis helps to identify 13 critical barriers, which are grouped into five categories, including cost and risk-related barriers, technical and cultural-related barriers, the government's role-related barriers, information and quality-related barriers, and market-related barriers. Among them, cost and risk-related barriers, including "concern about the high initial cost", "risks and uncertainties involved in adopting new materials", and "perception of the extra cost being incurred", are the three most critical barriers to CBBM adoption in Flanders. Kendall's W test shows good consensus among the two expert groups-with and without hands-on experience in utilising CBBMs-in their rankings of the barriers. Meanwhile, the Mann-Whitney U test indicates no statistically significant differences in the ranks of barriers between the two expert groups. The interview results confirm almost all survey results and provide deeper insights into the status and barriers to adopting these materials. Practical and policy implications are discussed based on these findings to inform policy deliberations on promoting CBBMs. This study may also be a good reference for scholars and industry practitioners to better understand issues impacting decision-making towards the adoption of CBBMs in the construction industry.

Well-being Effects of a Subsidy Retention Fund for Renovation of Dwellings of Locked-in Owners in Ghent.

With its subsidy retention fund, the city of Ghent targets homeowners, who live in a dwelling of bad quality and do not have the resources to renovate or move out. Being in this no-choice situation, they are locked-in homeowners. Through this innovative policy instrument, Ghent aims to improve the quality of its housing stock targeting households who may not take up other renovation-encouraging instruments. To reach the households who would otherwise not be able to renovate, important efforts in outreaching and offering technical and social guidance accompany the renovation subsidy. Guidance activities substantially increase the cost of the instrument, but in reaching the households living in bad-quality houses, it has the potential to create major benefits not only technically but also socially as housing quality is related to well-being. Generally, the identification of a causal relationship is difficult as well-being and its mediators are complex matters. This case offered a unique opportunity to collect information from the beneficiaries on a range of well-being domains both before the renovation of their dwelling and after the renovation. Even though the research was restricted to short-term effects, the results suggest that improvements in different domains of well-being can be linked to the improvement of housing quality. These improvements in well-being in Ghent show that (local) government spending in housing renovation of locked-in homeowners can be an instrument to achieve social progress.