Interoperability vs. Tradition: Benefits and Challenges of Web of Things in Building Automation

Building automation (BA) enables energy-optimized operation of buildings and eases the monitoring and maintenance of their utilities.
The heterogeneous and dynamic environment of a building creates a challenge for BA to support flexible deployment where programs should be able to semantically reason about the physical process and controls.
Towards addressing this challenge, we looked at W3C's Web of Things (WoT) recommendations which address the problem of interoperability in the IoT domain by using machine-understandable descriptions of protocol bindings and interactions, along with architectural patterns that are scalable to different deployment scenarios.
We introduced WoT concepts in our BA products in incremental implementation steps, which were deployed in real-life building installations.
Our findings based on the evaluation of a successful product deployment show that the WoT architecture along with its core concept of \textit{Thing Descriptions} may serve as a holistic mechanism for capturing knowledge and unifying interactions in BA.
As a contribution to both BA industry and research, we demonstrate how the W3C WoT can unify control function descriptions and process data in a non-intrusive and brownfield-compatible way, which is highly relevant for BA and similar industries.
In our work we substantiate how the unifying effect of WoT fits naturally to traditional BA system to establish interoperability, and further, opens up the possibility to make it truly autonomous.