Wireless Mesh technology has emerged as a new one for next-generation wireless networking to provide a wide variety of applications that cannot be supported directly by other wireless networks. With the recent emergence of standards, wireless solutions are ready to be deployed in building automation networks. For both new and old structures, wireless networking is expected to improve the existing applications and open up new ones. Wireless Mesh Networks (WMNs) deployed in building automation systems is at an early stage; however, as more and more building functions and applications are controlled electronically and wirelessly, the use of WMNs will offer distinctive advantages in the field of commercial and residential buildings. This paper surveys the developments and applications of WMNs in building automation and control systems and sketches the contours of the directions to achieve our goal towards highly energy-efficient buildings while maintaining a healthy, productive, and safe indoor environment.