Get the Whitepaper called I Own Your Building (Management System). It discusses various systems used to manage buildings and associated vulnerabilities with them.
You can download it from the following link: https://packetstormsecurity.com/files/download/155264/ioybms_gk_2019.pdf
Source: https://packetstormsecurity.com/files/155264/I-Own-Your-Building-Management-System.html