Study On Life Cycle Carbon Emission And Life Cycle Cost Of Green Buildings

The World Economic Forum has listed climate change as one of the five most destructive and possible global risks in the next decade.The governments of China and the United States have also raised climate change to a "climate crisis".In order to deal with the challenges brought by global climate change,China put forward the goal of "committing to peak carbon dioxide emissions before 2030 and achieve carbon neutrality before 2060" at the 75 th U.N.General Assembly.As a major carbon emitter in China,the construction industry accounts for 30% ～ 50% of the total carbon emissions of the whole society every year.Given such a high proportion,if we want to achieve carbon neutrality,the construction industry is bound to face great challenges.As a kind of sustainable building,green building is an effective way to achieve building carbon neutrality.However,the green building evaluation standard in China is lack of quantitative indicators of building carbon emissions,and the high initial construction cost also restricts the popularization and promotion of green buildings.Therefore,it is of great significance to study the life cycle carbon emission and life cycle cost of green buildings.This thesis summarizes the latest research on green building evaluation systems,life cycle carbon emission and life cycle cost of buildings.Compared with the world’s advanced green building evaluation systems,China’s green building evaluation system still has many shortcomings.In addition,there are few studies on life cycle carbon emission and life cycle cost of green buildings at home and abroad.Therefore,this thesis studies the life cycle carbon emission and life cycle cost of green buildings.The research contents and results mainly include the following aspects:(1)Based on the life cycle assessment theory and combined with the characteristics of green buildings,this thesis establishes a life cycle carbon emissions accounting model of green buildings,and summarizes the effective methods of carbon emission control in each stage of building from the perspective of building life cycle.(2)In the traditional building life cycle cost system,the cost of environmental impact caused by corporate or personal activities during the building life cycle is not considered.Based on the carbon tax policy,this thesis combines the life cycle assessment theory with the life cycle cost theory to establish the green building life cycle cost estimation model considering building carbon cost,and clarifies the main body of the building carbon cost in each stage.(3)Based on the above model,this thesis calculates and analyzes the life cycle carbon emissions and life cycle cost of an actual engineering case,as well as the life cycle performance of main green building measures.The calculation results show that although the green building energy-saving measures can effectively reduce the operation carbon emissions,the carbon emissions and costs of the building operation and maintenance stage still account for the largest proportion in the whole life cycle.If the time span of each stage is considered and the total carbon emissions of each stage are allocated to each year,the annual carbon emissions of the building material production and transportation stage are much higher than those of the building operation and maintenance stage.In addition,compared with the operation carbon emission,the "embodied carbon emission" brought by building materials production is more difficult to reduce.Therefore,in order to achieve carbon neutrality of buildings,in-depth research should be carried out on the emission reduction technology of embodied carbon in buildings.This thesis provides a method for measuring carbon emissions and costs of green buildings,which can lay a foundation for incorporating quantitative indicators of building carbon emission and economic benefit into the green building evaluation system in the future.Moreover,the calculation of the green building life cycle carbon cost can also provide a certain reference for the carbon emission reduction policy in the construction field.