Smart buildings tend to democratize both in new and renovated constructions aiming at minimizing energy consumption and maximizing comfort. They rely on dedicated networks of sensors and actuators orchestrated by management systems. Building networks are often heterogeneous, leading to complex management systems having to implement all the available protocols and resulting in low system integration and heavy maintenance efforts. Typical building networks offer no common standardized application layer to build applications. We propose in this paper to leverage on the Web-of-Things (WoT) framework, using well-known technologies like HTTP and RESTful APIs to offer a simple and homogeneous application layer. We outline the implementation of a gateway using the principles of the WoT to expose capabilities of the KNX building network as Web services, allowing a fast integration in management systems.