The emergence of wireless communications technology has led to an increasing interest in sensors that are free from wiring constraints that increase the cost of installation of a sensor network and create a confusing collection of wires in a building. In this work, the use of a wireless sensor network for a building monitoring application has been explored through a demonstration in a residence. A wireless mesh network was set up to monitor the performance of a heat pump system, a water heater, and a section of the building envelope. The installation of these sensors occurred incrementally, showing the ease with which a sensor network can be set up and expanded with mesh technology. Details of the hardware and software involved in setting up the network have been provided along with lessons learned from the installation.