Full Life Cycle Cost-benefit Analysis Of Existing Building Exterior Wall Thermal Insulation And Energy Saving Reconstruction

The acceleration of urbanization and industrialization has severely restricted the economic and social development due to resource and environmental problems.The government-led construction energy-saving renovation project is a product of the energy-saving and emission-reduction environment.It is a people's livelihood project,which is highly dependent on the government and unsustainable.The initial investment cost of energy-saving transformation is high,the public does not see direct benefits,and the market enthusiasm is not fully mobilized,which hinders the development of this type of project.This article takes the government of the social welfare representative as the main body and uses the whole life cycle cost theory to analyze the cost-effectiveness of the reconstruction project.This theory is mainly used for the decision-making of construction projects.This article focuses on the cost-benefit evaluation of reconstruction projects;and expands it to make a more detailed classification and calculation of the initial cost of reconstruction.By dividing the reconstruction project into different stages,determining the cost structure,establishing a calculation model,calculating the cost-effectiveness,and evaluating whether the reconstruction project is feasible and effective.This will deepen the public's understanding,mobilize the market enthusiasm,and promote the sustainable development of China's building energy-saving renovation projects.The comprehensive cost-effectiveness of the energy-saving renovation of residential buildings was measured through actual cases.The results show that: 1)the company's overall net present value,there are more cases of modification throughout the life cycle,greater than 0.Besides,the payback period is less than the service life of the building,which means that the investment cost can The building can be recovered during the use period,and the transformation has a good return on investment.2)The material cost accounted for the largest proportion of the incremental cost of the transformation.The energy-saving transformation of the building envelope should actively explore innovative technologies to produce low-cost and high-value insulation materials to enhance the transformation.3)The proportion of external wall heat dissipation before and after the transformation of the main parts of thebuilding envelope is reduced,and the proportion of external windows is increased.The part of external walls in the transformation cost is increased,and the cost can be controlled through technological innovation.4)The rise in energy prices has significantly improved the overall benefits of the transformation.With the change of energy-saving requirements,the role of investment cost in the initial stage of transformation has obviously deepened on the benefits of the transformation project.It is pointed out that controlling the initial cost is the key to energy saving transformation.