This report provides a summary and analysis of the presentations, discussions, and recommendations made at the ECAP 20 workshop held on 2–6 December 2019 in Japan. The five-day workshop consisted of “presentation of country reports”, “lectures”, “site visit”, “discussion”, and “presentation of action plans”, under the theme of “harmonious development of BECs/GBCs to strengthen and refine the AEA system, and introducing advanced technology such as ZEB in the ASEAN area with the help of Japan.” Attendees from nine AMSs (Brunei Darussalam, Cambodia, Lao PDR, Malaysia, Myanmar, Philippines, Singapore, Thailand, and Vietnam) actively participated in the workshop, resulting in productive discussions and action plans that are presented in the following. The agenda of the workshop and the list of participants are given in Annex-1 and Annex-2, respectively.