The pursuit of sustainable development has resulted in a narrow focus on environmental sustainability in construction. In recent years, the concept of holistic sustainability in the construction sector has gained traction, with green-certified buildings being a major driver. However, studies have shown that green building certification does not necessarily embrace a holistic sustainability approach. Moreover, the misconceptualisation of sustainability has remained a barrier to the full adoption of sustainability principles in the industry. Under this premise, a study was carried out amongst practitioners on green-certified projects to explore their understanding of sustainability in construction. The study was conducted through semi-structured interviews with construction professionals, who were involved in green building certified projects. Findings reveal that although green building practitioners have a considerable understanding of the concept of sustainability, the certification process limits the operationalisation of the concept. The context of South Africa was used to generate results that are relevant to other contexts with similar settings and green certification tools. The implication of this study includes the need for further research on the operationalisation of social and economic sustainability concepts in green building certification.