This paper presents a network-based fire-detection system via the controller area network (CAN) to evaluate the feasibility of using such a home automation protocol in a smart home. In general, a conventional fire-detection system has several shortcomings, such as weakness to noise, because it uses an analog transmission with 4-20 mA current lines. Hence, as an alternative to the conventional system, this paper describes the structure of a CAN-based fire-detection system and the design method of a CAN communication network. The performance of the proposed system is evaluated through experimental tests. The CAN has several advantages, such as low cost and ease of implementation, as compared to the other low layers of the BACNet, such as Ethernet or ARCNET. Therefore, if the CAN is selected for the low layer of the BACNet, a home automation system can be implemented more effectively.