Improve the carbon emission accounting system in the construction sector to support green and low-carbon development in urban and rural construction.

Recently, the country has continuously issued the "Opinions on Fully and Accurately Implementing the New Development Concept to Achieve Carbon Peak and Carbon Neutrality" (hereinafter referred to as the "Opinions") and the "Action Plan for Carbon Peak Before 2030" (hereinafter referred to as the "Plan"), making overall arrangements for carbon peak and carbon neutrality work.

Establishing a carbon emission accounting system is a fundamental task to support the dual carbon goals. The central document particularly emphasizes the need to "accelerate the establishment of a unified and standardized carbon emission statistical accounting system." The National Carbon Peak and Carbon Neutrality Work Leading Group Office has specially established a carbon emission statistical accounting working group. The carbon emissions from the entire process in the construction sector (including building material production, construction, and operation of existing buildings) exceed 50% of the national total carbon emissions, making it a key area for achieving the national dual carbon goals. However, there are significant shortcomings in the quantification of carbon emission data in the construction sector, including an imperfect building energy consumption statistical system, incomplete carbon emission accounting methodologies and standards, and an inadequate data sharing mechanism, which restrict the setting, decomposition, and implementation of carbon emission quantification targets in the construction sector. A sound carbon emission accounting system in the construction sector needs to be established urgently.

Facing Problems and Shortcomings

The building energy consumption statistical system needs improvement. First, China's energy consumption statistical system has not yet aligned with international standards, and building energy consumption has not been separately accounted for as a category of energy consumption, but rather mixed with various fields of energy consumption, which is the fundamental reason for the lack of authoritative statistical data on building energy consumption in China. Second, the statistical reporting system for energy consumption in civil buildings in China needs further improvement. Although the Ministry of Housing and Urban-Rural Development began implementing the statistical reporting system for civil building energy consumption as early as 2010, the survey work is conducted through a hierarchical administrative order, with most provinces and cities ultimately passing the survey tasks down to grassroots street departments. Due to a severe shortage of grassroots personnel, lack of professional knowledge, and facing many issues such as difficulties in coordination and lack of work funding, the quality of statistical data is difficult to guarantee. Statistics is a highly specialized task, and administrative order-based surveys do not align with the development direction of modern statistical systems.

The methodology and standard system for carbon emission accounting in the construction sector have not yet been established. In 2019, China released the "Standard for Carbon Emission Calculation in Buildings," which is the first national standard related to carbon emissions in buildings, applicable to the calculation of carbon emissions throughout the entire lifecycle of building construction, operation, and demolition. Under the current dual carbon background, this standard cannot meet the development needs of urban and rural construction. On one hand, the standard does not adequately consider prefabricated buildings, making it difficult to meet the carbon emission accounting for prefabricated building construction. On the other hand, the dual carbon work in urban and rural construction also involves carbon emission accounting for municipal facilities such as sewage treatment, construction/real estate enterprises, and newly built urban areas, and the methodologies and standard systems for such carbon emission accounting have not been established.

The mechanism for sharing building carbon emission data has not yet formed. This is mainly reflected in three aspects: first, the data sharing channels for energy, gas, water, and heating used in buildings have not yet been opened; second, due to the lack of relevant institutional support, the official data related to building energy consumption is inconvenient to disclose, such as data from civil building energy consumption statistical reports and large public building energy consumption monitoring platforms; third, a nationwide unified platform for building energy consumption and carbon emission data has not yet been established.

Establishing and Improving System Mechanisms

Improve the statistical monitoring and measurement system for building energy consumption. The "Opinions" point out that "we should improve the energy consumption statistical monitoring and measurement system in industries such as electricity, steel, and construction, and strengthen the construction of online monitoring systems for key energy-consuming units." To improve the statistical monitoring and measurement system for building energy consumption, the following three aspects of work should be done: first, improve the building energy consumption statistical reporting system. The reform direction of China's building energy consumption statistical system should align with international standards and be incorporated into the national energy statistical system. It is suggested that the energy consumption statistics for residential buildings be incorporated into the national household survey system, and the energy consumption statistics for public buildings and urban centralized heating should be further improved based on the civil building reporting system. Second, collaborate with the electricity department to promote the construction of a public building energy consumption monitoring platform guided by user needs. Summarizing previous experiences and lessons, the construction of the public building energy consumption monitoring platform in the new era should be based on market-oriented means, guided by the energy management needs of owners, downplaying the concept of "regulation" so that users can truly utilize it, ensuring the platform's long-term sustainable operation. At the same time, collaborate with the electricity department to introduce big data from electricity to ensure the accuracy and reliability of monitoring platform data. Third, accelerate the promotion of heating measurement reform, incorporating terminal heating into the building energy consumption statistical system.

Establish a carbon emission accounting standard system for various fields and levels of urban and rural construction. The "Plan" states, "Support industries and enterprises to conduct research on carbon emission accounting methodologies based on their characteristics and establish a sound carbon emission measurement system." To improve the carbon emission accounting standard system in the urban and rural construction sector, the following multi-level standards should be established: first, carbon emission standards for prefabricated building components, constructing a carbon emission factor database; second, carbon emission accounting standards at the project level for buildings and municipal facilities; third, carbon verification and accounting report standards at the organizational level for construction enterprises and real estate enterprises; fourth, carbon emission accounting standards at the regional level for new urban construction; fifth, carbon accounting standards for urban and provincial levels in the urban and rural construction sector.

Build a data sharing mechanism for carbon emissions in the urban and rural construction sector. The "Opinions on Promoting Green Development in Urban and Rural Construction" propose, "Establish a data sharing mechanism for urban building water, electricity, gas, and heating, enhancing building energy consumption monitoring capabilities." First, establish and improve the public and sharing system for building carbon emission data, clarifying the responsibilities and obligations of energy-consuming units, energy supply units, and government authorities regarding data disclosure or sharing, and strictly enforce relevant regulations. In fact, the public disclosure of building energy consumption data in China is legally based, for example, the "Regulations on Energy Conservation in Civil Buildings" stipulate that the people's governments at or above the county level should disclose the energy consumption of heating, cooling, and lighting in government office buildings and large public buildings within their administrative regions to the public. Second, build a platform for sharing building energy consumption and carbon emission data. Accelerate the establishment of a data information sharing platform for building energy consumption and carbon emissions, integrating various data such as macro-regional building energy consumption and carbon emission data, building energy consumption statistical data, monitoring data, corporate carbon disclosure data, building project carbon emission data, building material carbon emission factors, and building component carbon emission factors, allowing information data to flow in the market, which may enable the use of big data methods for analysis, generating new models and opportunities for building energy conservation and emission reduction. Third, research and develop tools for mining and analyzing building carbon emission data. For example, based on national standards, develop a universal building carbon emission calculation tool, integrating corresponding methodologies and a dynamically updated emission factor database to meet the mandatory requirements for carbon emission calculations proposed in the "General Specification for Energy Conservation and Renewable Energy Utilization in Buildings."

The construction sector faces a series of difficulties and challenges in achieving carbon peak and carbon neutrality. Urbanization in China is still ongoing, the building area has not yet peaked, and the energy demand of the people is still growing... Major issues must be addressed in detail. Without reliable carbon emission data in the construction sector, it is impossible to understand the current situation, let alone formulate practical carbon reduction plans. Improving the carbon emission accounting system in the construction sector and doing a good job in the foundational work of building carbon emission data will provide a basis for achieving the dual carbon goals in the construction sector.