Photo 1. Group photo of AJEEP Carbon Neutrality Diagnosis at the Ministry of Development of Brunei Darussalam 

The ASEAN Centre for Energy (ACE), the Energy Conservation Center Japan (ECCJ), and the Department of Energy (DOE) at the Prime Minister’s Office successfully co-organised a Carbon Neutrality (CN) diagnosis and Zero Energy Building (ZEB) Workshop in Brunei Darussalam. Held from 26 – 28 August 2025, the Ministry of Development (MOD) building 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 Brunei Darussalam. 

The CN diagnosis in Brunei Darussalam 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 Development, Department of Technical Services, Department of Building Services, Department of Mechanical and Electrical Services, Authority on Building Control and Construction Industry, DOE at the Prime Minister’s Office, ECCJ, and ACE attended the event.  

The programme 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 and in the Philippines at the Baguio Ayalaland Technohub in 2024, creating replicable models for effective energy management throughout the region. 

  Photo 2. Opening session featured remarks from Shirley Sikun of Department of Energy at the Prime Minister’s Office of Brunei Darussalam (left), Dr. Yoshitaka Ushio of ECCJ (middle), and Mardika Firlina of ACE (right). 

The opening session of the three-day event was attended by several distinguished guests, including the Permanent Secretary at the Ministry of Development, the Acting Permanent Secretary (Energy) at the Prime Minister’s Office, and the First Secretary at the Embassy of Japan to Brunei. The event was officially launched with remarks from Shirley Sikun, Director of the Energy Transition Division at DOE, Prime Minister’s Office, Dr. Yoshitaka Ushio, Senior Advisor of the International Cooperation Division at ECCJ, and Mardika Firlina, Technical Officer of the Energy Efficiency and Conservation Department at ACE. 

Following the opening session, the CN diagnosis participants engaged in several sessions. Mardika Firlina from ACE gave a presentation to explain the AJEEP Scheme 5 and the expected outcomes from the CN diagnosis. Tatsu Ito and Tomonao Aoki 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 Aiman Yusri Zainal Abidin from the Department of Technical Services, MOD, who shared the MOD building profile. The MOD is a seven-level commercial building with an estimated built-up area of approximately 7,000 square meters. The building also has a flat roof that is suitable for solar panel integration. 

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 office and lavatory/hallway on each of the 1st to 6th 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 Ministry of Development Building 

On the third day of the CN diagnosis, Tatsu Ito from ECCJ presented the results of the field survey and measurements. He also proposed improvement measures for areas such as energy efficiency, indoor environmental quality, and sustainable site management. These measures included replacing windows with double-glazing low-e vacuum glass, upgrading to the latest LED lighting with motion sensors, and installing inverter controls for air conditioning pumps and fans.  

Photo 5. Discussion on Carbon Neutrality diagnosis field survey and measurement results led by Tatsu Ito from ECCJ (right) 

Following the field survey in August 2025, an online interim meeting is scheduled for 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. 

ZEB Workshop  

Concluding the CN diagnosis activities on the third day morning, the ZEB Workshop in Brunei Darussalam was held in the afternoon of the same day at the Dewan Bertabur, Ministry of Development, to promote the ZEB concept and technologies. The Workshop accommodated about 50 in-person participants, including representatives from the Ministry of Religious Affairs, Ministry of Health, Ministry of Foreign Affairs, Ministry of Education, Ministry of Culture, Youth and Sports, and the Ministry of Primary Resources and Tourism. 

  Photo 6. Group photo of Zero Energy Building (ZEB) Workshop at the Ministry of Development of Brunei Darussalam 

The workshop commenced with opening remarks from Shirley Sikun of the DOE Brunei and a video message from Yoshino Yoshiomi, Director for International Policy on Carbon Neutrality, Ministry of Economy, Trade and Industry (METI) of Japan, setting the stage for a collaborative discussion on cleaner energy technologies. 

Photo 7. Video opening message from Yoshino Yoshiomi, Director for International Policy on Carbon Neutrality, Ministry of Economy, Trade and Industry (METI) of Japan 

The first half of the ZEB Workshop featured insightful presentations aimed at promoting ZEB initiatives. Dr. Yoshitaka Ushio from ECCJ, presented on ZEB promotion and the legal framework in Japan, followed by Mardika Firlina from ACE, who shared information on ASEAN Energy Awards ZEB winners and ZEB initiatives in ASEAN.  

Zulfadli Abu Bakar, Head of Energy Efficiency and Conservation Unit, DOE at the Prime Minister’s Office, provided an overview of the energy efficiency policy landscape in Brunei Darussalam. Concluding the pre-break session, Dr. Masato Miyata from National Institute for Land and Infrastructure Management Ministry of Land, Infrastructure, Transport, and Tourism, conducted an online presentation on the standard Japanese simulation system for ZEB, known as WebPro, and the analysis of accumulated data. 

Photo 8. ZEB Workshop: Shirley Sikun, Director of the Energy Transition Division, DOE at the Prime Minister’s Office (left) and Dr. Yoshitaka Ushio, Senior Advisor of the International Cooperation Division, ECCJ (right) 

Following the break, the workshop continued with a focus on practical applications and technology. Tatsu Ito from ECCJ delivered a brief report on the ZEB Diagnosis conducted in the MOD building. The session also included an introduction to Japanese Business Alliance for Smart Energy Worldwide (JASE-W) by Katsuhiko Yamamoto, with Japanese companies showcasing their technologies and products, such as AGC Inc.’s low-e glass by Jun Donomae and Sanken Setsubi Kogyou Co., Ltd.’s radiant cooling by Saeki. The workshop concluded with a Q&A session, a discussion, and closing remarks by Shirley Sikun of the Department of Energy. 

Photo 9. ZEB Workshop: Zulfadli Abu Bakar, Head of Energy Efficiency and Conservation Unit, DOE at the Prime Minister’s Office (left), Mardika Firlina, Technical Officer, ACE (right) 

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.