Photo 1. Group photo of AJEEP Carbon Neutrality Diagnosis at the Institute of Technology of Cambodia
Phnom Penh, 21 – 23 January 2026 – The ASEAN Centre for Energy (ACE), in collaboration with the Energy Conservation Center, Japan (ECCJ), and the Ministry of Mines and Energy of Cambodia successfully co-organised a Carbon Neutrality (CN) diagnosis and Zero Energy Building (ZEB) Workshop in Cambodia. Building J of Institute of Technology of Cambodia (ITC) was selected for CN diagnosis, fostering a collaborative effort to reduce carbon emissions, promote energy efficiency in the building, and raise awareness of the ZEB concept in Cambodia.
The CN diagnosis in Cambodia is part of the ASEAN-JAPAN Energy Efficiency Partnership (AJEEP) Scheme 5 Fiscal Year 2025 - 2026, which promotes carbon neutrality in buildings across ASEAN. Representatives from the Ministry of Mines and Energy of Cambodia, ITC, ECCJ, and ACE attended the event.
The program aims to identify potential CO2 emission reductions and energy savings within a specific building and to develop a ZEB retrofit proposal that provides recommendations for achieving significant energy efficiency improvements. This initiative builds upon successful diagnoses conducted in Thailand at Phra Nang Klao Hospital in 2023, the Philippines at the Baguio Ayalaland Technohub in 2024, and Brunei Darussalam at the Ministry of Development Building in 2025, creating replicable models for effective energy management throughout the region.
Photo 2. Opening session featured remarks from Sok Leng (Department of Technique and Energy Policy), Khemrath Vithean (ITC) , Dr Yoshitaka Ushio (ECCJ), and Sophea Lun (ACE).
The event was officially launched with remarks from Sok Leng, Deputy Director, Department of Technique and Energy Business Policy, Ministry of Mines and Energy of Cambodia, Dr Yoshitaka Ushio, Senior Advisor of the International Cooperation Division at ECCJ, Khemrath Vithean, Researcher at ITC, and Sophea Lun, National Project Coordinator of Cambodia, Energy Efficiency and Conservation (EE&C) Department at ACE.
Following the opening session, the CN diagnosis participants engaged in several sessions. Nathania Adella Panjaitan from ACE gave a presentation to explain the AJEEP Scheme 5 and the expected outcomes from the CN diagnosis. Dr Yoshitaka Ushio of ECCJ then explained the plan for the CN diagnosis activity and field survey, which included setting up measurement instruments for collecting and analysing data. This was followed by a presentation from Khmerath Vithean from the Department of Industrial and Mechanical Engineering, ITC, who presented the profile of Building G. Building G is a seven-storey academic building, completed in 2022, with an estimated total floor area of approximately 7,930 m2. The building accommodates a mix of functions, including offices, classrooms, research laboratories, and experimental laboratory spaces, with classrooms and office areas accounting for the largest share of floor use.
Photo 3. CN Diagnosis presentation and discussion session before the field survey
The field survey and measurement installation started on the afternoon of the first day and continued into the second day. A variety of instruments were installed to understand the building's operational conditions and create an energy model. These included an illuminometer, loggers for measuring CO2, temperature, and humidity, a clamp-on power logger, and a thermal camera. The instruments were set up at the lecture hall, office, and laboratory on each of the 1st to 7th floors, as well as at the chiller, Air Handling Unit (AHU), distribution panel, and outside air.
Photo 4. Field survey and measurement installation at the Institute of Technology of Cambodia
Following the field survey in January 2026, an online interim meeting is scheduled for 29 January 2026 to discuss data analysis and the ZEB retrofit design proposal based on simulation tools. This will be followed by a startup meeting in August 2026. At this meeting, the mid-to-long-term plan for CO2 reduction will be presented, and the necessary steps to achieve the building's CO2 reduction goals will be discussed.
Concluding the CN diagnosis activities on the third day morning, the ZEB Workshop in Cambodia was held in the afternoon of the same day at the Institute of Technology of Cambodia, to promote the ZEB concept and technologies. The Workshop accommodated about 50 in-person participants, including representatives from the Ministry of Mineral and Energy of Cambodia, ITC, intergovernmental organisation, private sectors, and university student.
ZEB Workshop and The Presentation of the Result
Photo 5. Group photo of Zero Energy Building (ZEB) Workshop at the Institute of Technology of Cambodia (ITC)
The workshop commenced with opening remarks from Sok Leng of the Ministry of Mineral and Energy of Cambodia, Rio Jon Piter Silitonga from ACE, and Dr Yoshitaka Ushio from ECCJ setting the stage for a collaborative discussion on cleaner energy technologies.
Photo 6. Opening Remarks from Sok Leng, Deputy Director, Department of Technique and Energy Business Policy, Ministry of Mines and Energy of Cambodia, Rio Jon Piter Silitonga from ACE, and Dr Yoshitaka Ushio from ECCJ
The workshop commenced with the scene-setting presentation delivered by Rio Jon Piter Silitonga from ACE, which provided an overview of Zero Energy Building (ZEB) developments in the ASEAN region. The presentation highlighted selected recipients of the ASEAN Energy Awards in the ZEB category, illustrating how leading projects across Member States have applied integrated design approaches, high-efficiency buildings systems, and renewable energy solutions to significantly improve building energy performance. In addition, the presentation outlined ongoing and emerging ZEB initiatives in ASEAN, including policy frameworks, capacity-building efforts, and regional knowledge-sharing platforms, thereby establishing a common reference point for participants and framing subsequent technical discussions within the broader regional of low-carbon and high-performance buildings.
The workshop then continued, Dr Yoshitaka Ushio from ECCJ, highlighting key findings on indoor environmental quality and energy performance. Field measurements showed that carbon dioxide concentrations within the classrooms exceeded acceptable thresholds during occupancy, indicating the need for improved ventilation control. In response, a set of integrated improvement measures was proposed, including optimisation of air-conditioning operation, high-efficiency lighting with sensor controls, enhanced ventilation management, inverter-driven pumps and fans, and envelope improvements such as low-emissivity glazing, alongside the consideration of rooftop solar photovoltaic integration to support progress towards ZEB performance.
Photo 7. Presentation and Discussion on Carbon Neutrality diagnosis field survey and measurement results led by Yoshitaka Ushio from ECCJ (right)
The workshop concluded with a Q&A session, a discussion, and closing remarks by Dr Sarin Chan from the ITC.
AJEEP is a regional cooperation initiative between ASEAN and Japan, under the ASEAN Senior Officials Meeting on Energy and Japan’s Ministry of Economy, Trade, and Industry (SOME-METI) Work Programme 2025-2026. Since 2012, implemented by ACE and ECCJ with financial support from METI, AJEEP has aimed to build capacity and narrow the gap between AMS on EE&C policies and measures. Starting in 2022, AJEEP entered into new Scheme 4 and Scheme 5. AJEEP Scheme 5 focuses on promoting advanced technologies for energy use toward Carbon Neutrality in the industry, building, and transportation through capacity building programmes.
