分析了绿色建筑节水项目直接增量成本和全生命周期增量成本的构成,采用净现值衡量指标的形式构建了含初始成本和未来成本在内的全生命周期增量经济模型,提出了直接增量成本的计算方法,并在西部某绿色建筑住宅小区节水示范项目进行模拟和算法应用比较.结果表明：该示范项目单位建筑面积直接增量成本为21.0元/m²,单位建筑面积全生命周期增量成本为31.5元/m²,表明该计算方法和经济模型具有合理性和实用性.

By analyzing the composition of the direct incremental cost and the incremental cost in the full life cycle of water-saving projects for green building,an incremental economy model,which includes both the initial and the future cost in the full life cycle,is established in the form of net present-value measurement index,and a method to calculate the direct incremental cost is proposed.Then,the model is simulated and the method is applied to a water-saving demonstration project for green building in West China.The results show that the direct incremental costs per unit construction area in the full life cycle are respectively 21.0 yuan per square meter and 31.5 yuan per square meter,which means that the proposed model and method are both reasonable and practical.