The Built Environment Application Platform (BEAP) takes forward the Common Spatial Data Infrastructure (CSDI) development strategy and provides a centralized platform for the development of applications covering aspects on city planning, infrastructure/engineering and environment to improve efficiency, transparency and support for decision making in planning and development, fostering interdepartmental cooperation and synergy. To tie in with the rapid urbanization around the world, the BEAP provides a valuable tool for users to help shape a better world and provide high quality services. The BEAP is developed on a cloud-based GIS solution to accommodate for different components to avoid single point of failure and enable future expansion. With the innovative use of various actionable datasets, the team developed 10 prototype applications to demonstrate the capabilities of the BEAP utilizing a digital twin approach and emerging technologies such as AI and BIM. In fact, the BEAP has already brought a significant amount of savings for its immediate users, which can further benefit a wide spectrum of stakeholders, from city-wide management to individual building owners, and ultimately citizens. It is envisioned that the BEAP can extend its services to not only the local Hong Kong context, but also to other cities in the world.