CBPM Conference 2026 · Vol. 2026, Issue 1

Making the case for sustainable buildings: Evidence from the limitations of conventional buildings

John Smallwood, Lungelo Dube and Eric Simpeh

Keywords: Conventional buildings, Energy efficiency, Indoor Environmental Quality, Lifecycle performance, Sustainable buildings

Abstract

Existing buildings face environmental, economic, and health-related challenges due to traditional construction methods, and the slow adoption of sustainable practices. The study investigates the impact this has on operating costs, marketability, indoor environmental quality (IEQ), and interior material durability for buildings in the Nelson Mandela Bay Metropole (NMBM). The quantitative approach entailed administering a Likert-type scale questionnaire among 65 East Cape Master Builders Association (ECMBA) general contractor (GC) members. The 21 surveys returned, resulted in a 32.3% response rate. The findings indicate that existing conventional buildings perform poorly compared to sustainable buildings in terms of operating costs, marketability, IEQ, and interior material durability. High operating costs were primarily attributed to inefficient occupant behaviour, frequent repairs or replacement of building systems, and dependence on grid electricity. The primary factors associated with reduced marketability include lower resale / rental value, outdated design or lack of modern visual appeal, and overall energy efficiency of the building. High internal humidity levels leading to dampness or mould, ventilation rate and air circulation, and inconsistent indoor thermal comfort were factors linked to IEQ and occupants’ health in existing conventional buildings. Recommendations include targeted policy intervention, improved regulatory enforcement, and increased industry awareness to accelerate sustainable practices.