Abstract: Integrated approach of extracting budget information from the building construction drawing is proposed. By analyzing the logic structure and various features of drawing information related to budgeting, the concept of engineering feature class is put forward. Employing the template based approach and pattern recognition, automatic extraction of budget information along with calculating the investment for multi-storey building structure is realized. It has been applied in the budgetary estimate and budgeting system based on the common CAD platform.