Japan's Plan to Quantify CO2 Emissions

The Japanese government is actively discussing a plan to require building owners and builders to calculate the lifetime carbon dioxide (CO2) emissions associated with their projects. This initiative aims to decarbonize the construction sector by quantifying the environmental impact of buildings throughout their entire life cycle, from construction to demolition.

The government hopes to finalize a schedule for implementing this plan by March 2024 and submit a related bill to the Diet in 2026. This plan will require owners of new buildings exceeding a certain size to conduct a life cycle assessment (LCA) to calculate the project's total CO2 emissions.

Procurement and manufacturing of materials: This includes emissions from processes like iron manufacturing, transportation, and heavy machinery use.

Emissions from construction activities and equipment will be factored in.

Energy consumption for heating, cooling, and other building operations will be considered.

Emissions from ongoing maintenance activities will be included.

Emissions from dismantling the building and waste disposal will be accounted for.

This comprehensive approach aligns with the European Union's initiative, which mandates CO2 emission calculations and disclosure for new buildings exceeding a certain size starting in 2028, expanding to all new buildings by 2030.

Calculating CO2 emissions during material manufacturing: Establishing a standardized methodology for quantifying emissions from this stage.

Determining the minimum building size that triggers the requirement for LCA calculations.

Establishing a transparent system for disclosing the calculated CO2 emissions.

The government's long-term goal is to introduce a cap on lifetime CO2 emissions for buildings. By quantifying emissions and encouraging builders to adopt low-carbon practices, Japan aims to significantly reduce the environmental impact of its construction sector.