Integration of Cost Planning in the Architectural Design of Housing

Cost estimation in the initial phases of a project is of great interest to the construction industry. This paper proposes a new way of the integration of an architectural project and its cost estimate so as to optimise the design solutions, according to technical and economic criteria. This work explores the capacity of an elemental cost estimation method for residential buildings, when integrated with Computer Aided Design systems, to increase cost estimate precision during the early stages of design. A Cost Planning and CAD model (CP/CAD) is developed by the integration of a database and a CAD system which provides for the automatic exchange of information relative to the geometric layout of the building, the construction element build-up and the construction costs of the same. Finally the CP/CAD model is tested through the estimation of costs for some theoretical cases and also for a group of one-family houses with similar architectural characteristics. The results show the increased precision and the advantages of the model for cost estimation in the early design stages.