Client Portal

5 Fundamentals Every Property Manager should know about Building Automation


When it comes to building automation systems (BAS), Property Managers tend to lean on their facilities operations team to tell them what is going on and what needs to be done. A BAS can be daunting to understand, but at the same time, it is responsible for a large portion of tenant satisfaction and operational budget. While a property manager or administrator does not need to know the ins and outs of operating a BAS, having a basic understanding of how these systems work and what to look out for when evaluating potential service partners can make all the difference.

tuIcgyfDHEEcHxQk6jEiOZ2FldlXOB3v1OVvKz5buyT1G9KGynrNd0MjPmwCHDxNiHM2f84HZwtC3ztwyTJlieZJOBXaVV1JvkSE fU HZH14Vmw4zwtqYiqyR8EGQGue6lPf5GS

The Components of a BAS

A slew of acronyms and HVAC terminology can be intimidating when trying to understand the various components of these systems, so we’ll keep this simple.

User Interface

This is the front-end software from which users program, monitor, and control the various components of the system.


Controllers can be broken into two main categories: Parent-Level and Child-Level (also known as sub-controllers or field-level controllers).

Parent-Level Controllers

These dynamic pieces of hardware are primarily used as a highway of communication between the user interface and child-level controller but can also directly control equipment and relay sensor data to the front-end.

Child-Level Controllers

Perhaps the most common version of a child-controller you’ll see is a variable air volume controller, also known as a VAV controller. These controllers tend to have more specific use cases and can also relay data from the sensors that are wired to them.

End Devices

This is a broad term for a variety of devices. End devices include instruments like sensors, valve and damper actuators, and relays all of which play specific roles in the building automation ecosystem.

Network Infrastructure

This the communication wire that carries messages between the user interface, controllers, and end devices. Most modern building automation systems utilize CAT 5/6 (typical blue ethernet cable) from the user interface to the controllers, and RS-485 wire from the parent-level controllers to the child-level controllers. Having a CAT 5/6 “backbone” in your building will allow you to deploy a variety of building automation technologies.

For a more detailed look at the operations of these components, check out this article on HVAC control systems and how they work.

“Open” isn’t always Open

So much has been made of using ASHRAE’s “open” communication protocol, BACnet, especially in the last 10 or so years. While BACnet is a common “language” used in building automation systems, many manufacturers have their own “dialects” and ways of concealing their proprietary messages. Even if you have a full BACnet system, chances are there is a proprietary tool or password required to fully program the system. Some manufacturers even encrypt their messages within the BACnet protocol.

BTL logo white 1

The point being, the questions you should be asking are not, “is your system open?” or “does your system use BACnet?”. Instead, you should ask questions about what you hope the end result of an open system would be, such as “what happens if our relationship sours and I want to use another service partner? What does that process look like? Are there any additional costs?”

Building Automation System Costs

The initial cost of a building automation system is driven by a variety of factors including:

  • Whether you are integrating with or replacing the existing system
  • The size and function of the space being conditioned
  • How many pieces and what type of equipment are being controlled
  • How precisely the environment needs to be monitored and/or controlled
  • Ongoing support/maintenance required and warranties

foisxpZOSrXD1hoEEPhMQm4SdObO6htxjd1q8X1W72pe8kzO0MiBAz5Bi VQLZyvlAELKgWCIFT1fwdqGYgDWt9Nd8cpZ 2mVf1eMoIbKo2q85aomOlN2NnJKItWUDFdWMl2XSzm

An important factor that does not get looked at often enough when evaluating these systems, is what they will cost to operate for the next 5, 10, or 15 years. It’s not uncommon to have the same BAS for over a decade so understanding the O&M costs is vital to managing your property’s budget. When evaluating ongoing costs, consider:

  • What recurring annual costs may come along with the system
    • Maintenance agreements
    • Software upgrades
  • Hardware failure
  • Hardware/Software Obsolescence
  • Length of warranties
  • Facility management time operating the system
  • Service calls – FM time chaperoning service partner
  • Potential energy costs/savings

How to calculate an ROI

As means of justifying your investments, you are often asked to provide an ROI analysis, but doing so with a building automation system is not as straightforward as doing so with an air handler replacement or LED upgrade.

Everyone’s first thought on generating an ROI for these systems is energy savings, but the fact is that there is no guarantee that a new BAS will provide a reduction in energy usage. It is simply a tool to manage and automate the biggest energy user in your building, the HVAC system. Ensuring the system is user-friendly enough for your operations staff to operate is your best bet towards generating savings here.

The most obvious opportunity to get a return on your investment is reducing operational costs outlined in the section above. Also consider less tangible returns such as:

  • Tenant retention
  • Occupant productivity
  • Other ways building engineers could be spending their time than responding to hot/cold calls
  • Life of mechanical equipment

How to evaluate potential service partners

Having a grasp on the above information is going to give you a phenomenal start to evaluating potential service partners for building automation. Beyond these items, you’ll want to use your previous experience as a guide to finding the right service partner. Give your candidates situational questions (from prior experiences) to see how they handle those scenarios. Get references from them and ask those references about a time their service partner came up short and how they reacted. If you are looking at an initial integration project, make sure you understand what the migration path forward looks like from that point.


Building automation service partners are unlike any other vendor in that they determine the health, safety, and efficiency of the built environment and chances are you will be working with them for many, many years to come. Rest assured that educating yourself on these systems is a good use of your time.

More to explore