从《建筑碳排放计算标准》看北京冬奥会场馆的低碳设计策略

Low-carbon Design Strategy of Beijing Winter Olympics Venues based on Standard for Calculation of Building Carbon Emissions

《建筑碳排放计算标准》是北京冬奥会场馆碳排放量核算依据,为了通过技术性引导来激发建筑师的创造力,结合实际运用来解读标准中所包含的设计策略。基于标准所构建的框架,从建材生产运输、建造及拆除、建筑运行三个阶段来总结冬奥场馆的低碳设计策略。建材生产运输阶段可通过数字化软件,选用低碳排放系数建材和当地材料,以及钢结构的轻量化来降低碳排放;建造拆除阶段可通过减少土方量,采用预制装配式技术和既有建筑改造等策略降低碳排放;建筑运行阶段可通过引入自然通风、自然采光,使用可再生能源,增加绿地碳汇等策略降低碳排放。

The 2022 Beijing Winter Olympic Games made a commitment to fully realize carbon neutrality. As the basis for calculating the carbon emissions of the Beijing Winter Olympics venues, the Standard for Calculation of Building Carbon Emissions(GB/T 51366-2019) has established a complete system framework from the perspective of carbon emissions in the whole life cycle of buildings, providing significant guidance for the low-carbon practice of green buildings. However, the contents expressed by the formula parameters in the standard are too theoretical. To guide the architectural design practice more conveniently,the contents in the calculation standard are summarized as design strategies, and the contents in the standard specification are understood by combining with practical application. The creativity of architects is stimulated through technical guidance.According to analysis of the Standard for Calculation of Building Carbon Emissions and from the perspective of the whole life cycle of buildings, the design strategies of low-carbon buildings were analyzed and summarized for three stages—namely, production and transportation of building materials, construction and demolition, and building operation.The case data of 25 venues for the 2022 Beijing Winter Olympics were collected and summarized, and the low-carbon design strategies included in the case were analyzed and summarized.In the production and transportation stage of building materials,the main parameters for calculation of carbon emission include the consumption of main building materials, the carbon emission factor of primary building materials, the average transportation distance of building materials, and the carbon emission factor of transportation distance per unit weight. The design strategies are summarized as follows according to the above four parameters: the consumption of main building materials can be decreased by using digital modeling and software calculation;the carbon emission factor of primary building materials can be decreased by choosing building materials with low carbon emission coefficients, and/or recyclable building materials;the average transportation distance of building materials can be shortened by choosing local materials;and the carbon emission factor of transportation distance per unit weight can be reduced by using lightweight steel structures.In the construction and demolition stage, the carbon emissions in the construction process mainly come from the engineering of the foundation and structural engineering. The design strategies for these two parts are summarized as follows: the carbon emissions of the foundation engineering can be reduced by reducing the earthwork volume, and the carbon emissions of the structural engineering can be reduced by using prefabricated assembly technology. In the demolition stage,reconstruction and reuse of existing buildings can decrease the carbon emissions of both the demolition stage and the construction stage of new buildings.In the construction operation stage, the main parameters for calculation of carbon emissions are the consumption of energy in the operation stage, the carbon emission factor of energy, and the annual carbon reduction of the green space system. The design strategies according to the above three parameters are summarized as follows:the energy consumption in the operation stage can be reduced by introducing natural ventilation and optimizing natural lighting;the carbon emission factor of energy can be reduced by using renewable energy(e.g., photovoltaic systems, wind power generation, solar water heating systems, heat pump systems);and the carbon sink of the green space system can be increased by increasing planting space and improving the carbon sequestration efficiency of plants.There are many low-carbon design strategies with Chinese wisdom in the venues for the Beijing Winter Olympic Games. The summary of low-carbon design strategies from the perspective of the whole life cycle can help architects to establish a complete and comprehensive understanding of low-carbon in practice, and to explore ideas for the sustainable development of relevant venues in the future, thus enabling the implementation of the new requirements and goals proposed by the standards and specifications. A low-carbon design concept with unified goals and strategies is established by summarizing design strategies from excellent practice cases continuously. This makes positive contributions to realizing the goal of "carbon peak and carbon neutrality".