By Yves Habchy
Reading the building automation room from outside the industry offers a unique view. You see the legacy protocols (BACnet/IP) humming along, the giants (Johnson Controls, Honeywell, Siemens) rolling out their agentic platforms (Pulse, Forge, Building X), and the open-source purists championing Project Haystack and Brick.
But there is a massive gap in the middle. It is the gap where the Magic happens—or where momentum dies. As an independent software engineer diving into the BAS space, I am calling it the Brick/Haystack-aware BACnet/IP MCP gap.
It sits uncomfortably between the polished, vendor-agentic announcements and the academic rigor of semantic tagging. And it is the single largest opportunity for the Independent Master System Integrator (MSI).
The “Instigator” Reality of 2025
To understand the tension, we have to look at the history of the metadata problem. In a 2015 piece for AutomatedBuildings.com, Marc Petock argued forcefully for “Making Device Data Self-Describing.” He knew then what we are fighting now: data without context is just noise.
Therese Sullivan expanded on this in 2017, noting that metadata tagging was the missing link between pure connectivity and actual intelligence. Fast forward to November 2025, and the “Instigator” articles on AutomatedBuildings correctly point out that the major vendors have finally listened—but they have built walled gardens.
Johnson Controls Pulse, Honeywell Forge, and Siemens Building X are brilliant. They leverage AI to manage their native stacks beautifully. But what about the 40-year-old chiller plant with BACnet points that don’t follow a modern ontology? What about the MSI who needs one pane of glass for a campus with three different vendor ECNet systems?
The Semantic Gap Explained
Here is the technical friction point.
Project Haystack and Brick are the answer to semantic interoperability. They tag a point not just as “AV-423” but as “AHU-1.Room-Temp_Sensor.” However, as argued in the research around the Brick+ ontology, there is a natural tension between informal tag-based systems (Haystack) that rely on idiom and convention for meaning, and formal ontologies (Brick) amenable to automated tooling.
For the independent MSI, this creates the Model Context Protocol (MCP) gap.
The vendor platforms have Agentic AI, but they are often “Brick-blind” to non-native assets.
The open-source tooling is Brick/Haystack rich, but lacks the enterprise agentic action layer.
The MSI sits in the middle, holding the keys to the translation layer.
Why the Independent MSI Wins
In the December 2025 MSI deep dive on AutomatedBuildings, and echoed by Brian Turner via Nexus Labs Ep #034, the role of the integrator is shifting from “wire puller” to “data architect.”
Vendors want to own the agent. Open source wants to own the schema. But neither wants to own the messy reality of a live, multi-vendor mechanical room.
Independent MSIs who master the semantic layer—who can ingest BACnet/IP, apply a Haystack tagging model, translate it to Brick, and then present a unified namespace to any agentic platform—are no longer subcontractors. They are the operating system.
Bridging the Gap
We don’t need another superglued digital twin. We need to smash the glued model apart, find the studs, and rebuild the building out of open, writable Lego bricks with one independent brain on top.
The tools are here: Niagara 5 offers a bridge, but it requires the MSI to configure the semantic model. The academic papers on Brick+ from 2020 proved the inference engine works.
Now, the industry needs the boots on the ground—the independent MSIs—to refuse to install “dumb” data. Charge for the semantic model. Own the namespace. If the data isn’t tagged, it isn’t commissioned.
The vendor platforms will come and go. But a well-tagged, Brick-validated building will be smart forever.
Sources & Further Reading
- Petock, M. (2015). Making Device Data Self-Describing. AutomatedBuildings.com.
- Sullivan, T. (2017). Metadata Tagging for BAS. AutomatedBuildings.com.
- Fierro, G., Koh, J., Nagare, S., et al. (2020). Formalizing tag-based metadata with the Brick ontology. Frontiers in Built Environment.
- ACM Digital Library. (2019). Beyond a House of Sticks: The Brick+ Ontology. Proceedings of the 6th ACM International Conference on Systems for Energy-Efficient Buildings.
- AutomatedBuildings.com Editorial. (2025). From Superglued Silos to Interoperable Bricks.
- Turner, B. Nexus Labs Ep #034. The Future of the Independent Integrator.
- AutomatedBuildings.com (Nov 2025). The Instigator: Agentic Platforms.
- AutomatedBuildings.com (Dec 2025). MSI Market Outlook.
About the Author
Yves Habchy is a full-stack software engineer researching the gap between independent MSIs and vendor agentic AI platforms in commercial buildings. He writes at habchy.dev and shipped a v0.1 alpha BACnet/MCP gateway at github.com/Yveshby27/brick-bacnet-mcp.
