In high rise building construction projects, curtain wall is one of the most widely used exterior finishing components and has a major influence on the overall building operational costs and efficiency in terms of CO2 emissions. The selection of curtain wall systems involves numerous technical, environmental and economic factors, and impacts on all project stages from concept design, through manufacture to installation and operation. The current way this important decision is being made in the business process, and its simplification, are two important issues that are still unexplored in the literature. After investigating the drawbacks of the current business process using a retrospective case study and an industrial survey, a decision support system (DSS), which consists of a process framework and an integrated relational database as a central repository for the main curtain wall systems and their engineering parameters, is proposed as a potential solution. The DSS developed not only enables the resolution of the main issue of the selection of curtain wall systems at the early design development stage but it also helps specifiers identify multiple technical and commercial options that could be presented to clients in real time.