Study On The Cost Benefit Of Green Building Projects In The Whole Life Cycle Based On SD Model

As the world enters the era of climate change,the ecological problems caused by the greenhouse effect are becoming increasingly serious,and China has put forward the goal of "double carbon" to improve the quality of the environment.As one of the major carbon emitting industries,the green transformation of the construction industry has become a necessity of the times,and the characteristics of green building with less pollution and lower energy consumption make it the future direction of construction development.At present,the cost-benefit evaluation system of green building residential projects is not yet perfect,which makes it difficult for various stakeholders in green building residential projects to make correct decisions,and the research on the cost-benefit of green building has become a hot direction in the current construction industry.In response to this situation,with the goal of promoting the low-carbon green development of the domestic construction industry,the cost-benefit evaluation system of green building projects is constructed based on the actual green building project case data,and the case is evaluated and analyzed by using the system dynamics model,in order to provide reference for the developers of green building projects in China to make correct decisions.The research contents of the thesis mainly include:(ⅰ)Based on the study of green building evaluation standards and literature related to green building cost-effectiveness,the necessity of whole-life cost-benefit research is clarified.(ⅱ)A comprehensive examination of the factors influencing the cost-effectiveness of green building residential projects is conducted,and an in-depth analysis is made from the perspective of developers to derive the factors influencing the technical costs and technical benefits of green buildings,and to clarify the mutual influence relationships among the factors.Taking the new version of Green Building Evaluation Standards as the benchmark,it is divided into five major technical cost indicators of safety and durability,health and comfort,convenience of living,resource saving and environmental livability,and three major technical benefit indicators of economy,environment and society.(ⅲ)The cost-benefit evaluation model of green building residential project is constructed through the research method of system dynamics model,and an example of green building residential A project in Ganzhou City is introduced for simulation.It is found that the long service life of the building,makes the cost input in the operation phase account for the highest proportion,reaching 50% of the total cost of the whole life cycle,followed by the construction phase input cost accounting for about 45%,while the cost invested by the resource-saving technology accounts for 80% of the construction phase input cost,which is the focus of the project cost control.Among the cumulative technical benefits in the whole life cycle,the economic benefits directly obtained account for 58%,among which energy saving generates the highest economic benefits,accounting for 70%.Social benefits account for 35% of the cumulative technical benefits,which should also not be underestimated.The project investment payback period is 7.41 years,and reasonably selects the green building technology,and the cost investment can realize the cost recovery through the benefit profit in a shorter period.(ⅳ)Based on the results obtained from the model simulation,suggestions are given to select the energy-saving rate design scheme for green building residential projects.The cost and benefit ratios vary for different energy efficiency rates,and the best cost-benefit is found in the simulation interval for project A with 65% energy efficiency.The selection of the appropriate green technology can optimize the cost and maximize the benefits.This paper makes up for the incompleteness of the research on the cost effectiveness of green building projects and constructs a cost effectiveness evaluation index system for green building projects,which has certain practical significance and value.