Carbon Reduction Strategies For Prefabricated Residence Under Embodied Carbon Control Targets

In the face of global warming caused by greenhouse gas emissions,China has actively responded to the call to sign the Kyoto Protocol and the Paris Agreement and made a commitment to reduce carbon emissions,and put forward the "double carbon" target by the end of 2020.As an industry with high energy consumption and high carbon emissions,the construction industry has long been of great significance in achieving the double carbon target,especially the operation phase,which accounts for a larger proportion of carbon emissions and is a key target for carbon reduction.With the development of green building technology,the energy consumption in the operation phase of the building is gradually reduced,and even "zero energy" buildings have emerged.At the same time,the proportion of carbon emissions from the whole life cycle of buildings,such as the production,transportation and construction of building materials,is increasing and has attracted the attention of academia.The embodied carbon in buildings is characterized by a large amount of emissions in a short period of time and cannot be changed once the design is determined,so early design decisions are of great importance to reduce the embodied carbon.For architects,early decisions in the design process are more implementable and controllable,and can effectively reduce the embodied carbon emissions of buildings.In this paper,we use the "QIJU" series of experimental houses,which are the entries of the Solar Decathlon China,as a sample of zero-energy buildings,and aim to classify the building systems according to the structural characteristics of different assembled small buildings,calculate the embodied carbon emissions at the system level,and correlate them with the design scheme to build a fast calculation method suitable for architects,and use the calculation results as a basis for program decision,so as to optimize the structure and floor plan of the building,etc.The main research work of this paper is as follows:First,it composes the characteristics of carbon emission composition of energyefficient buildings,researches the theory and calculation tools of carbon emission,determines the method of calculating embodied carbon of buildings using carbon emission factor method and building information software,constructs the calculation path of embodied carbon of buildings,and uses the annual average carbon emission intensity of buildings to measure the level of carbon emission of buildings.Secondly,it introduces the design overview of the study case of this paper--QIJU series experimental residence,analyzes the carbon emission composition of the two buildings respectively,compares the carbon emission results,summarizes the problems in the calculation,and puts forward the idea of feedback the carbon emission calculation results to the architectural scheme design.Subsequently,according to the design and construction process of Qiju 3.0,the building system is divided according to the level of "standard parts-component-hanger",starting from two aspects of optimization components and optimization hanger respectively.With the aim of reducing embodied carbon,multi-scheme comparison and selection of Qiju 3.0 is carried out.Combined with Revit-Tally,components before and after optimization design are calculated and analyzed.The decision basis is obtained,and the possible problems and solutions are summarized.Finally,according to the above results,carbon reduction strategies in the process of architectural design are summarized to provide suggestions for architects in building carbon reduction design,and the shortcomings of this study are pointed out,and further suggestions are put forward for the development of building carbon emission calculation tools.