Editor’s Note: This month we take a dive into our vault, revisiting the Building Automation column that was printed five years ago, in August 2017, by longtime Engineered Systems columnist Ira Goldschmidt, P.E.

Integration of a variety of non-BAS controls and systems has become an increasingly important aspect of building projects. These controls/systems range from packaged HVAC equipment to “fully engineered” mechanical systems (e.g., VRF and lab controls) to non-mechanical equipment/systems (lighting controls, electrical equipment, security, fire alarm, etc.) and even to building operations or enterprise systems (e.g., energy management/tracking, CMMS, tenant billing systems). And the Internet of Things (IoT) has the potential for further accelerating this trend.

This has led to an increasing number of projects that are integration-intensive (i.e., integration of non-BAS controls/systems has become a major portion of the scope versus that of the core BAS installation efforts). Therefore, I thought it useful to revisit the notion of “who should do system integration.” This is a question that has been floating around for years without any definitive conclusion to date. Arguments have been made about whether a BAS contractor should be the system integrator versus whether system integration should be provided by a separate contractor operating at a different level/location in the construction hierarchy (e.g., the division 23 versus 25 argument).

What are System Integrators?

The challenge to this discussion is that there is no clear agreement about what a system integrator should be doing. Is system integration a BAS-centric activity, since many non-BAS controls/systems are currently integrated to the BAS? Would system integration be better provided (i.e., less finger-pointing) by a contractor that provides no controls or systems but is instead a master of integrating anything to anything else (which appears to be the CSI division 25 model)? Finally, should system integration be provided by a “technology” contractor (CSI division 27) whose primary expertise is IP communications but has the expertise to expand into integration if not also control systems?

BAS Contractors as System Integrators

BAS contractors are currently the de facto system integrator for most, if not all, projects. There is little evidence that BAS won’t continue to be the “hub” for building integration, so this may not change anytime soon. But, is this the best approach? In my experience, the BAS contractor as “system integrator” leads to several problems. First, their focus is primarily on HVAC controls, since that is their core expertise but also because they are typically a sub to the mechanical contractor. Therefore, any integration work, especially with non-mechanical systems, seems to be a low priority that often leads to project delays or incomplete work. Secondly, the BAS contractor, as the BAS provider, is usually not an objective partner when integration challenges arise. Lastly, due to their position in the construction contractor hierarchy, they have no authority over the providers of non-BAS controls/systems and therefore are often hamstrung in their integration efforts.

System Integration as a Separate Contractor

Would a different type of contractor operating at a different position in the construction contractor hierarchy be a better system integrator? Not too long ago, some BAS contractors were attempting to rebrand themselves as “system integrators.” In some cases, this just seemed to be a marketing exercise, while in other cases there was a serious attempt to broaden their services (i.e., adding IP infrastructure, lighting control, security, etc.). Unfortunately, this did not seem to change how non-BAS, low-voltage systems are delivered and/or integrated on a construction project. More recently, I’ve seen efforts by “technology” consultants and contractors to also broaden their expertise into other low-voltage building systems and integration. Once again, I’ve seen nothing to indicate this approach is being considered as a compelling alternative to the construction industry’s status quo.


I do see merit in combining broad low-voltage system and integration expertise under one contractor’s responsibility and/or to separate those that provide the controls/systems from that responsible for integrating them. Perhaps this issue needs to start with change at the design level (e.g., should “technology” consultants design all low-voltage systems along with any integration requirements?). But, is no new idea, however helpful, going to ever be considered by the A/E construction “good old boys” club, or is this a case of the BAS contractor as system integrator being the worst approach except for all others?

Ira has worked in the building industry for more than 35 years as a controls tech, MEP designer, and consultant providing design/guidance for critical-facility BAS and intelligent building systems integration. He is a co-author of the ASHRAE BACnet® standard and Guideline 13 — Specifying DDC Controls.