ABSTRACT
The quest for economic growth in most developing countries has resulted in huge demand for construction projects, and this has eclipsed crucial sustainability concerns (Zhang et al., 2014; Change et al., 2016). Therefore, the governments in many countries are increasingly aware of their responsibility to ensure sustainability, leading to the identification of sustainability strategies (Aarseth et al., 2016) to improve reported lower practices in the construction industry (Zoufa & Ochieng, 2017). Because there is an existing correlation amongst the elements of the identified strategies (Aarseth et al., 2016), however, the nature of their inter-relationships is not known. By neglecting the nature of the inter-relationships, existing research has failed to identify key strategies and develop a well-structured model to work as a whole, articulated towards guiding and facilitating experts towards sustainable practices. The key objectives of the study were to identify and assess the sustainability strategies, develop a model from the resulting interrelationships and finally classify those strategies based on their level of influence. Data was collected through the use of 18 Semi-structured interviews to source the expert's opinion from industry practitioners and academics comprising architects, builders, engineers and quantity Surveyors. Interpretive Structural Modelling (ISM) methodology was used to analyse the inter-relationships amongst the elements of sustainability strategies. Using the ISM approach, the present work is able to distinguish and prioritize the strategies according to their driving power and dependencies. The result shows that "Setting sustainability policies by the government" was found to be the key factor or the high priority strategy, influencing the implementation of all the other strategies. Also, the study was able to develop the ISM model based on the resulting interrelationships among those strategies into 7 different ranks. The ISM model so formed, serves as a normative guide or action plan to construction practitioners and other key stakeholders towards sustainable management of their construction projects. Also, the eight elements of the sustainability strategies were classified into independent strategies, dependent and quadrants of MICMAC graph. None of the strategies were found in the autonomous quadrant, signifying that all of the strategies are significant in achieving sustainability in the management of construction projects. The government should therefore, develop measures to ensure that its sustainability policies are strictly adhered to, which helps in achieving organisational and project level strategies. Because the ISM model is not statistically validated, further studies should aim at validating the results of this study with use of a linear equation modeling such as structural equation modeling technique (SEM).