The focus of research has mainly been on the life cycle approach to project development, while limited attention has been given to the ageing construction companies that make all these activities/processes happen. This paper examines the organisational factors determining the sustainability and growth of building and civil engineering contractors in South Africa. The paper explores whether there are specific organisational factors that aid the sustainable development and growth of contractors in the South African construction industry. The paper analyses data gathered from face-to-face interviews conducted with four established and twelve upgraded and successful building and civil engineering contractors listed on the Construction Industry Development Board’s (cidb) Register of Contractors. The aim of the study is to identify the organisational factors critical for sustainable contractor development and growth in South Africa. The study found that organizational factors responsible for the sustainable development and growth of construction contractors include the size of the founding team members, management capabilities, strategic decisions made by founders/leaders and the ability of the company to constantly evolve, adapt and respond effectively to threats/challenges whenever they surface, amongst other findings. Capacity to generalise the results of the study to the large cidb registered contractor group is limited by the smallness of the sample size. Future research should make use of a larger sample size to obtain more general findings. The results of the study imply that the founding team size, experience, entrepreneurial and managerial capabilities, capacities and organisational structures that enable the efficient response of companies to external and internal challenges are key components of the definable arrangements that will support the sustainability and growth of construction organisations. The paper is of value to government departments and agencies such as the cidb and contracting firms in the construction industry.