||Construction projects pass through several phases during their life cycle. However, during the initial level where feasibility studies are conducted, conceptual estimates are generated to assist decision makers in approving or rejecting proposed projects. The common practice followed during this level starts by consultations between owners, practitioners and experts with the deficiency of documents, specifications and drawings. Own experience and wide range of assumptions control the preparation of conceptual estimates, where extensive assortment of errors and unsound decisions are anticipated to occur. Therefore, the availability of accurate cost data is necessary to overcome this problem. This is achieved by the relevance of Management Information System, where cost data and 3D-CAD drawings can be stored and manipulated to fit user's needs. Moreover, decision makers are in need for a reliable system to use during the feasibility stage of new proposed projects. This paper presents the design and implementation of a decision support system, which helps in selecting the best project type given the budget. The system integrates 3D-CAD drawings with relational databases so that any modification in the drawing's parameters such as: floor area, floor-to-floor height and building perimeter: will result in the generation of a new conceptual estimate taking into consideration the required adjustments.