Thesis (MTech (Construction Management))--Cape Peninsula University of Technology, 2017. / The study investigates the predominant factors responsible for increase in the cost of building materials and the effect of this cost increase on housing delivery in Western Cape, South Africa. Sustainable housing is buildings produced to meet the present housing needs of people without conceding the ability of the future generation to meet their future needs. However, a significant increase in the cost of building materials has been a major constraint to the delivery of sustainable housings, as made evident in the literature, leading to project cost and time overruns or even project abandonment. However, building materials consume up to 65% of the total cost of construction. This factor on cost has, over the years, threatened the ability of the construction industry to deliver projects within budgeted cost, at stipulated time, and at satisfactory quality. This prompted the need to proffer solutions to these factors identified which are causing increases in the cost of building materials towards sustainable housing delivery in Western Cape. Based on this research study, housing is termed to be sustainable when it is available and affordable for the masses timely and at quality expected. The research study adopted a mixed methodological approach, involving the use of semi-structured qualitative interviews and closed-ended quantitative questionnaires administered to construction stakeholders (architects, quantity surveyors, engineers, construction managers, project managers, site supervisors and material suppliers) in the Western Cape Province of South Africa. SPSS version 24 software was used for analysing the quantitative data collected and ‘content analysis’ method was used to analyse the information collected through the qualitative interviews. The findings revealed that the major factors responsible for increasing the cost of building materials are inflation, wastages of building materials by labourers, cost of transportation and distribution of labour, design changes, client contribution to design change and change in government policies and regulation. Moreover, the research showed that fluctuation in the cost of construction and high maintenance costs due to poor workmanship also impact the cost increase of building materials for housing delivery. In addition, research findings affirmed that for optimum materials usage for the enhancement of sustainable construction, the following criteria should be considered in the selection of building materials: maintenance cost, energy consumption and maintainability. The adoption of these findings by construction stakeholders in the South African construction industry would enhance the delivery of affordable housing at reduced cost, at the required time and at the expected quality. Therefore, an adequate implementation of the framework presented in this study will enhance sustainable housing delivery.