Study On Water Saving Standard Refinement Of Green Building Assessment System

China's evaluation standard for green building has been implemented since 2006,guiding and evaluating the development of green building in China over the past few years. But today, with the development of economy and the change of the market,many defects have appeared during the evaluation, and it is not sufficient to better guide further development of green building. Based on this situation, this paper will study on water indexes of green building standard to meet the development requirements of green building.First study the water index and evaluation method of 8 green building assessment system, emphatically compare their differences with the existing green building standards, the study find that the water index at home and abroad all covers three main aspects: the non-traditional water, water-saving appliances and equipment, water supply and drainage system design, and individual indicators are not included. But foreign standards focus on quantitative indicators, clear categories and clear purpose,while domestic has comprehensive index system, few quantitative index and each index is interrelated. Then the concept of incremental costs are studied, and the starting point for water incremental cost is accurate defined, and formulate the water incremental cost research steps and form preparing for the subsequent research work.Then 55 green building carry out investigation and analysis, the first analysis of55 projects in the evaluation of green building is the choice of water indexes and the standard rate of these options, the result finds the probability of each index of water that in the chosen are relatively large, suggesting there no indexes especially difficult and water indexes are more reasonable. Then the incremental cost of the project and water incremental cost is studied, the general rule is: the incremental cost increases with increasing the degree of evaluation, there is also a big difference between the same grade, this reflects the cost index is not set in the evaluation system. In order to reduce the same level gap, we need to formulate water saving cost control value for different grades. Then water-saving and water-saving efficiency amount are studied,and it embodies the same rules with the incremental cost, and green technology portfolio in a given area is not necessarily suitable for other areas.In order to find the most suitable technology portfolio for each star of different areas, a large number ofresearch projects are needed.At the end, we reclassify water indexes of green building standard. The water indexes is mainly divided into four aspects: the non-conventional water, water-saving appliances and equipment, system design and other. On the basis of four aspects, these indexes are divided forced and option items. Then refine and quantify the options and with a recommendation technology related to facilitate the design units to choose.Combined with the third chapter selection analysis and investigation of actual project incremental cost, the green building water level division score and cost control value are given.