Green building planning demands a high level of coordination among various disciplines to meet sustainability goals, yet current practices often fail to provide a structured and transparent collaborative process. Although collaborative planning is a foundational principle, the roles and interactions of planners throughout the stages remain poorly defined, which obstructs the realization of fully coordinated project development. Building Information Modeling (BIM), despite its potential to support teamwork across stakeholders, is still applied in siloed environments and limited to certain project entities. These conditions restrict information exchange and hinder transparency among stakeholders. On the other hand, blockchain technology offers a decentralized and tamper-resistant system for recording transactions, which can improve data transparency, traceability, and trust among project stakeholders. Therefore, this study aims to develop a green building planning workflow by integrating blockchain technology into BIM. The proposed approach enables the exchange of information among planners to be managed using a distributed ledger system based on Hyperledger Fabric. A qualitative method was used, involving literature study and prototyping to examine how planning workflows can be aligned with blockchain technology. The results indicate that the planning process can be modeled using blockchain, but the integration requires a custom application to enable communication between BIM and Hyperledger Fabric. This integration proposes a transparent and secure foundation for structured collaboration in green building planning.