Studies On The Environmental Impact Of The Building Industry In China Based On The Life Cycle Assessment

The impact of building industry on the environment runs through building's life cycle and also is a complicated issue. Some problems which do not conform to the sustainable development concept also exist during the rapid development of building industry. Therefore, the Life Cycle Assessment (LCA) methodology was adopted in this research, to analyze the integrated environmental impact, development trend and possible energy-saving measures of building industry in China.Firstly, theoretical research for applying building LCA in macroscopical field was carried out for. The common aim of building LCA and the principles for defining study scope were discussed. Then the end-point damage oriented model was chosen to be the Life Cycle Impact Assessment (LCIA) method for buildings in China base on the comparison of several LCIA methods. The sensitivity of normalization benchmark was also analyzed. Also, an integrated assessment method combining building life cycle environmental performance and economic performance was proposed.Secondly, the research method on the time effectiveness of product Life Cycle Inventory (LCI) was presented and the LCI with time effectiveness of several types of energy, building materials and building equipment were established. This provides method and data to solve the problem of lacking product LCI in China. The calculation of product environmental load with time effectiveness show that the environmental load of electricity and most building materials decrease year by year, among them, the environmental load of steel decreases most obviously.Thirdly, the total environmental impact of the whole building industry from 1990 to 2005 was quantified, and the possible development trend of it from 2006 to 2030 was predicted. The results indicate that, at present, the environmental load of building industry in China mainly comes from the building component production of new constructed buildings and the operating energy consumption of existing buildings, the former contributes more than 50%; The environmental load of rural buildings is higher than that of urban residential and commercial buildings; the per capita environmental load of building industry in the city is higher than that in the country. Fully fulfilling the various energy-saving and pollutant-reducing measures associated with various fields can reduce the accumulative environmental load of building industry from 2006-2030 by 52%. Controlling construction speed with effort is most effective, should be implemented as soon as possible. The effect of operating energy-saving will become more and more obvious with the increase of the floor area of existing buildings.Finally, two kinds of building energy-saving techniques, insulation and Building Integrated Photovoltaics (BIPV), were analyzed with LCA. The conclusions drew are different from those drew from the analysis only of operating energy saving. There is an optimal insulation thickness for the residential building in every zone, which reduces gradually from northern area to southern area. The actual energy-saving effect of BIPV system is greatly dependent on the location where it is used and the way in which it is installed. So the location and installation mode with short energy payback time should be selected for application and promotion in priority.The methodology and conclusions in this paper can be the reference to the sustainable development plan of the building industry in China.