Sales forecasting has a great impact on facilitating effective and efficient management of resources for construction projects. Since, having appropriate sales prediction provides appropriate financial activities, especially for large scaled construction projects. This study proposes a numerical model for construction projects which integrates Fuzzy Rule Based System (FRBS) with Net Present Value (NPV) analysis. In the proposed hybrid model, FRBS is used for sales forecasting and provides input for NPV formulation. The proposed model is applied to a construction project in Istanbul so as to demonstrate its performance and practicality for real life problems.