We are developing wireless building management systems without changing the building protocols (e.g., BACnet, MS/TP). This makes incremental deployment possible.
See our technical report here. Our programming codes can be downloaded here (there is a readme file inside). We have a video (~90MB) for wireless BMS. Please use real player to watch it. This demo has been shown in ICCPS 2012.
Apart from Arduino sensors, we also develop Imote2-DDC connection, see some photos.
Here is a recent technical report on our work to reduce the electricity bills of commercial buildings. We release our source code for physical modeling (EnergyPlus, TinyOS for wireless sensor networks, etc).
We have some previous works (technical report on this) on green buildings.