Provision of Affordable Housing Through Tunnel Formwork as an Innovative Approach for Sustainable Development in Urban South Africa

Against a backdrop of South Africa’s lack of sustainable affordable housing in South Africa, high levels of spatial inequality, and low developer margins, the study examines the potential of tunnel formwork to provide sustainable and economically viable affordable housing. Using a mixed-methods approach, the research combines survey data from built-environment professionals with desktop analyses of municipal planning frameworks, project financial models, and Lightstone Property transactional datasets. The empirical findings reveal a clear implementation gap: although interest in sustainable construction methods is high, local technical knowledge remains low. Specifically, 70.8% of surveyed professionals have never visited a tunnel formwork site, and 65.2% report limited familiarity with the system. Major strengths include the widespread focus of developers on upfront capital cost reductions over schedule acceleration, despite the high upfront shuttering costs of R25,000/m² being a significant barrier. Secondary data explains this paradox by showing that tunnel formwork yields a net cost advantage of 5.9% to 13.0% only when achieving a repetition threshold of 450 to 500 reuses. However, 47.8% of developers rely on phased, piecemeal construction methods that prevent reaching this scale. When combined with land constraints, bulk infrastructure backlogs, and regulatory delays under SPLUMA, the planned projects become unaffordable for the target market. The study concludes that tunnel formwork cannot succeed as an isolated technical, it requires an integrated, multi-stakeholder delivery system. To make this operational, municipalities should release well-located serviced land and streamline planning approvals. Concurrently, national government needs to offer upfront concessional financing, equipment grants, regional demand aggregation, and accredited artisan training to achieve the required scale and local technical capacity. Effect of Varying Coconut Shell Ash and Eggshell Powder Blend Ratios on Oxide Compounds Matthew Kwaw Somiah1*, Mohammed Deen-Halis Zebilila2 Frederick Owusu Danso3, Isaac Yaw , Manu4, John Bentil5, Wilberforce Adjei Sakyi6 1,3,4,5 Faculty of Bui