1、The development plan of building energy conservation and green building is published
1.1 Green buildings help energy conservation and carbon reduction
On March 11, 2022, the Ministry of Housing and Urban-Rural Development issued the 14th Five-Year Plan for Building Energy Conservation and Green Building Development. The Plan points out that the overall development goal of the green building industry during the “14th Five-Year Plan” period is that by 2025, all new buildings in cities and towns will be completed as green buildings, the building energy utilization efficiency will be steadily improved, the building energy structure will be gradually optimized, the growth trend of building energy consumption and carbon emissions will be effectively controlled, and a green, low-carbon and circular construction and development mode will be basically formed. Lay a solid foundation for peaking carbon in urban and rural development before 2030.
Specifically, the development goals of the Plan are that by 2025, over 350 million square meters of existing buildings will be renovated to conserve energy, over 50 million square meters of ultra-low energy consumption or near-zero energy consumption buildings will be built, and prefabricated construction will account for 30% of new urban buildings in that year. The installed solar photovoltaic capacity of new buildings in China will exceed 50 million kilowatts, and the area used in geothermal energy buildings will exceed 100 million square meters. The renewable energy replacement rate for urban buildings will reach 8 percent, and electricity consumption will exceed 55 percent of building energy consumption.
“Plan” defines the key tasks of building energy conservation and green building industry during the “14th Five-Year Plan” period, including: 1) improve the quality of green building development: strengthen the construction of high-quality green buildings, improve the green building operation management system; 2) Improve the energy-saving level of new buildings; 3) Strengthening energy-saving and green renovation of existing buildings: improving the energy-saving level of existing residential buildings and promoting energy-saving and green renovation of existing public buildings; 4) Promote the application of renewable energy: promote the application of solar energy in buildings, strengthen the utilization of renewable energy such as geothermal energy, and strengthen the construction and management of renewable energy projects; 5) Implementing building electrification projects; 6) Promoting new green construction methods; 7) Promoting the popularization and application of green building materials; 8) Promote regional building energy coordination; 9) Promoting green city development.
1.2 The goal of the 14th Five-Year Plan has been improved compared with the 13th Five-Year Plan
The Ministry of Housing and Urban-Rural Development recently released the 14th Five-Year Plan for Building Energy Efficiency and Green Building Development, which is more comprehensive and in-depth than the 13th Five-Year Plan for Building Energy Efficiency and Green Building Development released in 2017. In terms of the setting of main goals, the 14th Five-Year Plan of green building further puts forward higher requirements for some indicators involved in the 13th Five-Year Plan on the basis of further completing the established goals of the 13th Five-Year Plan. At the same time, in order to better achieve the goal of carbon peak by 2030 and carbon neutral by 2060, it added some new development goals: 1) By 2025, the total energy consumption of primary and secondary buildings in operation is controlled at 1.15 billion tons of standard coal equivalent; 2) Construction of 50 million square meters of ultra-low energy consumption and near-zero energy consumption buildings during the 14th Five-Year Plan period; 3) The installed solar photovoltaic capacity of buildings increased by 0.5 billion kw during the 14th Five-Year Plan period; 4) The application area of geothermal energy buildings will be increased by 100 million square meters during the 14th Five-Year Plan period; 5) By 2025, the proportion of electricity consumption in building energy consumption will reach 55%.
2、Background: Building energy conservation is crucial to energy consumption targets
The 14th Five-Year Plan for Building Energy Conservation and Green Building Development, It was issued on the basis of the 14th Five-Year Plan for National Economic and Social Development of the People’s Republic of China and the Outline of the Long-range Goals for 2035, the Opinions of the CPC Central Committee and The State Council on Fully, Accurately and Comprehensively Implementing the New Development Concepts to achieve carbon Peak and carbon Neutrality, Opinions of the General Office of the CPC Central Committee and The General Office of the State Council on Promoting Green Development in Urban and Rural Construction.
2.1 Our carbon emission reduction planning is clear, “double carbon” steadily progress
Since the reform and opening up, China’s economy has grown steadily and rapidly. In 2010, China’s GDP surpassed Japan’s to become the second largest economy in the world. With the rapid development of economy, China’s total carbon emission has also increased rapidly, surpassing the United States in 2006 and ranking first in the world. Under the increasingly severe pressure of international emission reduction, the carbon emission of our country has become one of the focus of global attention.
In order to achieve the goal of peaking carbon emissions by 2030, many domestic scholars have proposed that China’s carbon emissions can peak around 2030 by actively adjusting industrial structure and energy structure, accelerating the transformation of development mode, encouraging the promotion of clean energy, and appropriately enhancing carbon sink capacity and other measures. At the same time, under the macro-control of the state, all provinces (municipalities) can achieve the target of reaching the peak of carbon emissions around 2030 by developing peaking plans that fit the actual situation. According to the analysis of literature related to peaking of carbon emissions in China by 2030 (Li Xiexiang et al.), scholar He Jiankun2 found through research that China can achieve the peak of carbon emissions in 2030, the peak will be less than 11 billion tons, less than 8 tons per capita; Researchers Chai Qimin 3 and Xu Huaqing4 found that China’s peak carbon dioxide emissions in 2030 can be controlled at 12 billion tons and 8.5 tons per capita.
In order to further analyze the path of deep decarbonization under the goal of carbon peaking and carbon neutralization, the National Center for Strategic Research and International Cooperation on Climate Change has developed the China Low Carbon Strategy Analysis Model (SACC). This model takes 2010 as the base year, takes into full consideration the changes in future economic growth and consumption demand, and combines with the analysis and international comparison of the changes in the development of technologies related to carbon emissions. It calculates that under the path of deep decarbonization, China’s carbon emissions will peak around 2030, with the peak level of carbon dioxide being about 11.5 billion tons. It will then gradually fall to 4.8 billion tonnes by 2050, equivalent to pre-2005 levels.
3、Transformation and upgrading of construction and building materials is imminent under the target of carbon peak
3.1 the total life-cycle carbon emissions of Chinese construction accounted for 51%
The construction industry is the world’s largest energy consumer and one of the most major greenhouse gas emission industries, its energy consumption accounts for more than 30% of the world’s final energy consumption, and about 40%-50% of global greenhouse gas emissions from the construction industry 8. According to the International Energy Agency’s (IEA) calculation of global energy consumption and carbon dioxide emissions in the construction sector, in 2018, the end-use of construction and operation-related energy in the global construction sector accounted for 36% of global energy consumption, of which building materials production accounted for 6%, residential construction accounted for 22%, and non-residential construction accounted for 8%. In 2018, the total carbon dioxide emissions related to the construction and operation of the global construction industry accounted for 39% of the global total carbon dioxide emissions, among which the production of building materials accounted for 11%, residential buildings (including direct and indirect emissions) accounted for 17%, and non-residential buildings (including direct and indirect emissions) accounted for 11%9.
4、Building quality improvement is the trend of The Times
4.1 Green building cannot be separated from the development of green building materials
According to the national “Green Building Evaluation Standards” (GB/T50378-2019), the definition of green building materials is: in the whole life cycle can reduce the consumption of resources, reduce the impact on the ecological environment, with energy saving, emission reduction, safety, health, convenience and recycling characteristics of building materials products. The development and cooperation of green building materials are indispensable for green building to realize the comprehensive performance of safety and durability, health and comfort, convenient life, resource saving (land saving, energy saving, water saving, material saving) and livable environment. Referring to the Implementation Rules of the Management Measures for the Evaluation and Labeling of Green Building Materials jointly issued by the Ministry of Housing and Urban-Rural Development and the Ministry of Industry and Information Technology in 2015 and the Technical Guidelines for the Evaluation of Green Building Materials, the assessment of green building materials is based on the carbon footprint assessment of the whole life cycle, not only for the building materials themselves but also for the emission requirements in the production process of building materials. Let’s take thermal insulation materials as an example. Technical Guidelines for Evaluation of Green Building Materials require that production enterprises should meet the basic requirements of production, and the assessment score of thermal insulation materials also runs through the whole life cycle of buildings.
5、Green Building/Building Materials: The “Blue Ocean” in the next five years
The impact of carbon emission reduction on the whole life cycle of buildings is a grand proposition, which also involves all aspects of the construction industry, and there are many possibilities for technological innovation in the future. Due to space limitation, this paper mainly focuses on prefabricated buildings, building insulation materials, BIPV, building vibration reduction and isolation, and evaluation system of green building materials.
5.1 Building external protection and insulation materials may have emission reduction space
Energy consumption in the running stage of Chinese buildings mainly includes heating energy consumption, cooling energy consumption, lighting energy consumption, household appliances energy consumption and cooking energy consumption. It is found that energy consumption of heating, cooking and household appliances are the main energy consumption activities. Under the support of the existing energy consumption technology, with the acceleration of urbanization in northern China, heating area will increase greatly, and residential energy consumption will increase significantly; At the same time, in the context of global climate change, the frequency of extreme weather will increase the energy consumption of the southern provinces. Cooling energy consumption is still the main energy use mode in the South.
As a result of the large climate difference between the north and the south of China, the carbon emissions of civil buildings in the northern region during operation are significantly higher than those in the southern region. 17. The promotion of passive low-energy buildings under the current conditions in China can significantly improve the living environment and reduce building energy consumption. If the newly built residential buildings in the northern heating region are built into passive houses (passive low-energy buildings), it will save 3.2 billion metric tons of coal by 2050 (the total amount saved in the 40 years from 2011 to 2050 by using 100% passive buildings compared with 65% energy-saving standard buildings) 18. The effect of energy saving and emission reduction is remarkable. There is a wide space for building insulation materials.
If the use of thermal insulation materials, increase the thermal insulation performance and air tightness of the building, reduce the demand for heating and refrigeration, it may effectively reduce the energy consumption and emissions in the running stage of the building. Thermal insulation materials are generally light, loose, porous fiber materials, thermal conductivity is the main index to measure the performance of thermal insulation materials. The smaller the heat conductivity coefficient, the less heat transmitted through the material, the better the thermal insulation performance, the material’s thermal conductivity coefficient depends on its composition, internal structure, bulk density, etc.
From the evaluation standard of green building materials, rock wool board thermal insulation performance is superior, in line with the requirements of energy saving; Fire grade A, in line with safety requirements; Mature technology, convenient construction, meet the convenience requirements; And its price in the main building thermal insulation materials moderate, is one of the most cost-effective building thermal insulation materials.
5.2 Development opportunities of green building materials evaluation
Green building materials refer to building materials that can reduce the consumption of natural resources and the impact on ecological environment in the whole life cycle, and have the characteristics of energy saving, emission reduction, safety, convenience and recyclability 22. The development of green building materials is an important measure to promote the transformation and reform of building materials industry and the development of green development.
Evaluation marking of green building materials refers to the activity of evaluating the building materials products applied for evaluation, identifying their grade and carrying out informational marking according to the technical requirements of evaluation of green building materials and the procedures and requirements determined in the Measures for Management of Evaluation Marking of Green Building. Among them, identification includes certificates and marks, with traceability. To carry out the evaluation and labeling of green building materials is an important measure to standardize, guide and strengthen the production enterprises related to building materials in the use of raw materials, processing production, quality control, engineering application and other aspects of quality, energy saving, environmental protection, safety and other aspects. Especially since 2013, many departments of the state have successively issued and issued policies and measures on vigorously promoting green building materials, which reflects the state attaches great importance to the transformation and upgrading of building materials industry and accelerating the development of green building materials industry.
