Obayashi Corporation Obtains Certification Based on Carbon Offset Third-Party Certification Standards
Obayashi Corporation, in collaboration with Idemitsu Kosan, obtained a third-party carbon offset certification by replacing construction site diesel with Idemitsu's carbon-offset fuel.
📋 Article Processing Timeline
- 📰 Published: April 23, 2026 at 19:02
- 🔍 Collected: April 23, 2026 at 10:31
- 🤖 AI Analyzed: April 24, 2026 at 03:53 (17h 21m after Collected)
Obayashi Corporation (Headquarters: Minato-ku, Tokyo; President: Toshimi Sato; hereinafter 'Obayashi'), in collaboration with Idemitsu Kosan Co., Ltd. (Headquarters: Chiyoda-ku, Tokyo; President: Noriaki Sakai; hereinafter 'Idemitsu Kosan'), has obtained certification based on the Carbon Offset Third-Party Certification Program (*1), for which the Ministry of the Environment provides guidelines. To obtain this certification, Obayashi implemented a carbon offset for CO2 emissions associated with fuel use by replacing a portion of the diesel oil used at its domestic construction sites with 'Idemitsu Carbon Offset fuel J (ICOFJ)' (*3), a fuel oil with attached J-Credits (*2) supplied by Idemitsu Kosan.
At construction sites, fuel such as diesel is used to operate construction machinery and vehicles, leading to the emission of fuel-derived CO2. Obayashi has thus far promoted various initiatives to reduce Scope 1 (*4) emissions, such as reducing fuel consumption, improving work efficiency, and replacing it with low-carbon fuels. However, it is not easy to immediately replace all the fuel used at construction sites with low-carbon fuel, and even as efforts to reduce CO2 emissions progress, there are cases where unavoidable emissions occur.
Given this situation, Obayashi has been considering the utilization of carbon offsets, including ICOFJ supplied by Idemitsu Kosan for companies taking on the challenge of carbon neutrality in the construction industry and others, on the premise of continuous efforts to reduce CO2 emissions. ICOFJ is endowed with credits certified under the J-Credit Scheme, and it can be used in various locations, including construction sites, just like regular fuel. The two companies have been collaborating on the verification of the next-generation biofuel 'Idemitsu Renewable Diesel (IRD)' (*5) since 2024, and this initiative to use ICOFJ is a further development of this collaboration.
Obayashi and Idemitsu Kosan will continue business activities that contribute to reducing environmental impact by promoting the reduction of CO2 emissions through methods that can be implemented at construction sites, such as optimizing fuel delivery according to the operating volume of construction machinery and visualizing fuel usage and CO2 emissions.
*1 Carbon Offset Third-Party Certification Program
A system managed by the Carbon Offset Association with guidelines provided by the Ministry of the Environment, wherein a registered certification body certifies initiatives by companies and organizations to offset hard-to-reduce greenhouse gases like CO2 with credits.
Obayashi Certification Number: CO2-1016
*2 J-Credit
A system operated by the Japanese government wherein the amount of reduction or absorption of greenhouse gases like CO2 can be certified and traded as 'credits'. By purchasing and retiring these 'credits', companies can offset their own emissions. Since they are generated by domestic projects (introduction of renewable energy, forest conservation, etc.), they also contribute to the local economy and environmental conservation.
*3 Idemitsu Carbon Offset fuel J (ICOFJ)
A high-value-added fuel oil sold by Idemitsu Kosan that attaches carbon credits to fuel oil, allowing the offsetting of CO2 emissions associated with fuel use. Users can offset their CO2 emissions through the CO2 reduction and absorption effects of the carbon credits while using the fuel as usual.
URL: https://www.idemitsu.com/jp/business/oil/lowcarbon/icof/index.html
*4 Scope 1
In the calculation standards for greenhouse gas emissions such as CO2, this refers to the portion directly emitted by the company itself (e.g., fuel use by construction machinery in construction works).
*5 Idemitsu Renewable Diesel
An alternative fuel to diesel manufactured by Idemitsu Kosan through hydrotreating oil-based raw materials such as waste cooking oil and vegetable oil. It is a carbon-neutral fuel where CO2 emissions are considered effectively zero compared to regular diesel.
URL: https://www.idemitsu.com/jp/business/oil/lowcarbon/renewable_diesel/index.html
[Company Profile]
Name: Obayashi Corporation
Headquarters: 2-15-2 Konan, Minato-ku, Tokyo
Representative: Toshimi Sato
Established: December 1936
Main Business: Domestic and overseas construction works, regional/urban development, other construction-related business, and contracting of engineering, management, and consulting services related to these, real estate business, etc.
Corporate Website: https://www.obayashi.co.jp/
Name: Idemitsu Kosan Co., Ltd.
Headquarters: Chiyoda-ku, Tokyo
At construction sites, fuel such as diesel is used to operate construction machinery and vehicles, leading to the emission of fuel-derived CO2. Obayashi has thus far promoted various initiatives to reduce Scope 1 (*4) emissions, such as reducing fuel consumption, improving work efficiency, and replacing it with low-carbon fuels. However, it is not easy to immediately replace all the fuel used at construction sites with low-carbon fuel, and even as efforts to reduce CO2 emissions progress, there are cases where unavoidable emissions occur.
Given this situation, Obayashi has been considering the utilization of carbon offsets, including ICOFJ supplied by Idemitsu Kosan for companies taking on the challenge of carbon neutrality in the construction industry and others, on the premise of continuous efforts to reduce CO2 emissions. ICOFJ is endowed with credits certified under the J-Credit Scheme, and it can be used in various locations, including construction sites, just like regular fuel. The two companies have been collaborating on the verification of the next-generation biofuel 'Idemitsu Renewable Diesel (IRD)' (*5) since 2024, and this initiative to use ICOFJ is a further development of this collaboration.
Obayashi and Idemitsu Kosan will continue business activities that contribute to reducing environmental impact by promoting the reduction of CO2 emissions through methods that can be implemented at construction sites, such as optimizing fuel delivery according to the operating volume of construction machinery and visualizing fuel usage and CO2 emissions.
*1 Carbon Offset Third-Party Certification Program
A system managed by the Carbon Offset Association with guidelines provided by the Ministry of the Environment, wherein a registered certification body certifies initiatives by companies and organizations to offset hard-to-reduce greenhouse gases like CO2 with credits.
Obayashi Certification Number: CO2-1016
*2 J-Credit
A system operated by the Japanese government wherein the amount of reduction or absorption of greenhouse gases like CO2 can be certified and traded as 'credits'. By purchasing and retiring these 'credits', companies can offset their own emissions. Since they are generated by domestic projects (introduction of renewable energy, forest conservation, etc.), they also contribute to the local economy and environmental conservation.
*3 Idemitsu Carbon Offset fuel J (ICOFJ)
A high-value-added fuel oil sold by Idemitsu Kosan that attaches carbon credits to fuel oil, allowing the offsetting of CO2 emissions associated with fuel use. Users can offset their CO2 emissions through the CO2 reduction and absorption effects of the carbon credits while using the fuel as usual.
URL: https://www.idemitsu.com/jp/business/oil/lowcarbon/icof/index.html
*4 Scope 1
In the calculation standards for greenhouse gas emissions such as CO2, this refers to the portion directly emitted by the company itself (e.g., fuel use by construction machinery in construction works).
*5 Idemitsu Renewable Diesel
An alternative fuel to diesel manufactured by Idemitsu Kosan through hydrotreating oil-based raw materials such as waste cooking oil and vegetable oil. It is a carbon-neutral fuel where CO2 emissions are considered effectively zero compared to regular diesel.
URL: https://www.idemitsu.com/jp/business/oil/lowcarbon/renewable_diesel/index.html
[Company Profile]
Name: Obayashi Corporation
Headquarters: 2-15-2 Konan, Minato-ku, Tokyo
Representative: Toshimi Sato
Established: December 1936
Main Business: Domestic and overseas construction works, regional/urban development, other construction-related business, and contracting of engineering, management, and consulting services related to these, real estate business, etc.
Corporate Website: https://www.obayashi.co.jp/
Name: Idemitsu Kosan Co., Ltd.
Headquarters: Chiyoda-ku, Tokyo