What is a Building Management System?

April 26, 2024

Efficiently managing a commercial building can significantly impact the bottom line, and that’s where the intelligent application of a Building Management System (BMS) comes into play. In 2022, 60% of commercial buildings over 50,00 square feet in the United States had a building management system (BMS).

Leveraging a BMS ensures optimal building performance, enhances tenant comfort, and drives down energy costs through integrated control and monitoring. In this blog we'll explore the following topics in relation to BMS systems.

What is a Building Management?

How Building Management Systems Work

Advantages of a BMS System

Challenges and Considerations

When is BMS a requirement? 

Cost of a Building Management

Major Building Management System Companies

What is a Building Management System?

Building Management Systems (BMS), also known as Building Automation Systems (BAS), are computer-based systems installed in buildings to control and monitor the building's mechanical and electrical equipment, such as HVAC, lighting, energy, fire systems, and security systems. 

In simple terms, the BMS serves as a central control point for all facilities within a building. 

Because the BMS can remotely control heating and ventilation systems from a computer or mobile device, facility management staff do not have to physically walk to each building, floor, or room to shut down, switch on, or manually adjust mechanical devices.

Here are some examples of what the BMS controls: 

  • HVAC Management: The BMS oversees duct conditions, including temperature, pressure, humidity, and exhaust heat levels, triggering alerts if they stray from preset thresholds and ensuring maximal HVAC energy efficiency.
  • Hot Water and Heating Control: Temperature regulation and pump operations for hot water and central heating are managed by the BMS, assuring proper distribution and functionality.
  • Chilled Water Oversight: Chiller functions, including temperature control and pump operations, are supervised by the BMS to guarantee proper coolant distribution.
  • Lighting Control: The system automates lighting operations, adjusting for optimal use and energy savings while maintaining comfort and safety standards.
  • Electrical Consumption Tracking: The BMS monitors electrical usage and the status of main power switches, offering insights into energy consumption and potential savings.
  • Fire Safety Sprinkler Oversight: Monitoring of the sprinkler system is incorporated to ensure adherence to fire safety protocols.
  • Security Systems Management: Surveillance and access control are integrated into the BMS, bolstering building security and response to incidents

In the below diagram, you can see a visual representation of the different systems a BMS controls, including: 

  • Air Handling Units
  • Heat Pumps
  • Energy Recovery Ventilators
  • Variable Refrigerant Fan Coil Unit (Typical)
  • Ducted Variable Refrigerant Fan Coil Unit in Ceiling
  • Condensing Unit

Because every piece of equipment in the building feeds data to one, single system, the BMS allows for well-informed decision-making, boosts efficiency, and curtails energy consumption, ultimately leading to cost savings and a green real estate.

How Building Management Systems Work

The truth is building management systems consists of both software and hardware components.

In the architecture diagram below, you can see an overview of the three main levels of the BMS System: field, automation, and management.

The first at the very bottom is the field level, consisting of the e-sensors, instruments, valves, actuators, thermostats, IO modules, etc. The field layer performs the following functions:

  1. Data Collection:
    • Sensors: Includes devices like temperature sensors, flow meters, humidity sensors, and occupancy detectors that gather real-time data on environmental conditions.
    • Meters: Monitors utility consumption (e.g., electricity, water) to track usage and efficiency.
  2. Control Execution:
    • Actuators: Devices such as valves and dampers that physically adjust system components based on control signals from the automation layer.
    • Controllers: Local devices that execute simple control tasks directly at the field level, such as opening or closing a valve.
  3. Communication:
    • Signal Transmission: Sends collected data and status updates to the automation layer via hardwired connections or Ethernet.
    • Feedback: Provides real-time feedback to the automation layer on the status and performance of various systems.
This diagram was created by Engineering Automation

Next, comes the automation level. The automation layer performs multiple functions.

  1. Data Consolidation:
    • Input Collection: The automation layer receives data inputs from various sensors and devices in the field layer. These inputs include temperature readings, flow rates, occupancy information, and more.
    • Data Aggregation: All these inputs are consolidated into the Direct Digital Controllers (DDCs) within the automation layer. This aggregation allows for a comprehensive view of the building's environmental conditions and systems' statuses.
  2. Data Processing:
    • Analysis: The DDCs analyze the collected data against predefined setpoints and operational parameters. This involves checking if the current conditions (e.g., temperature, humidity) match the desired conditions set in the system.
    • Decision Making: Based on the analysis, the DDCs decide what actions need to be taken to maintain or achieve the desired environmental conditions. This might include turning on or off equipment, adjusting valve positions, or changing air flow rates.
  3. Control Actions:
    • Signal Transmission: After making decisions, the DDCs send control signals to the relevant field devices. For example, if the temperature is too low, the DDC might send a signal to open a hot water valve or turn on a heating unit.
    • System Regulation: These control actions help regulate the building’s systems to maintain optimal conditions. This ensures that the building environment is comfortable for occupants and operates efficiently.
  4. Communication with Management Layer:
    • Data Reporting: The automation layer communicates with the management layer, providing a higher-level overview of the building's operations. This is typically done through Human Machine Interfaces (HMIs) or other supervisory software.
    • Adjustments and Alarms: Users in the management layer can use HMIs to adjust setpoints, respond to alarms, and monitor overall system performance. The management layer can send new setpoints or operational commands back to the automation layer as needed.

This diagram was created by Engineering Automation

Lastly, is the management level. Via a human machine interface or computer, program, the management level displays all the information taken from the field level by the controllers in a graphical user interface.  The management layer performs the following functions:

  1. Data Interaction:
    • Monitoring: Provides real-time data visualization through Human Machine Interfaces (HMIs) or supervisory software, allowing operators to view system status, alarms, and performance metrics.
    • Adjustments: Enables operators to modify setpoints, schedules, and operational parameters to ensure the building's environment meets desired conditions.
    • Alarms: Displays and manages alarms, allowing operators to respond promptly to system issues or deviations from setpoints.
  2. Control:
    • Command Transmission: Sends high-level control commands and new setpoints to the automation layer for execution.
    • Override Capabilities: Allows manual override of automated controls for maintenance or in response to specific events.
  3. Data Analysis and Reporting:
    • Trend Analysis: Collects historical data for analysis to identify trends, optimize performance, and predict maintenance needs.
    • Reporting: Generates reports on system performance, energy consumption, and other key metrics for decision-making and regulatory compliance.
This diagram was created by Engineering Automation

Now that you understand a BMS system's architecture, we can look at the individual hardware and software parts:

Hardware Components:

Control Panel:

The control panels are the core of a BMS, installed within a plant room and wired directly to the building's systems. They serve as the central command centers where data is received, processed, and commands are issued. The controllers within the automation layer are located within the BMS control panel.

A BMS control panel in a commercial office building would look like this:

A BMS Control Panel shown by Sander Mechanical Service


Sensors are deployed throughout the building to collect data on environmental conditions and system performance. They play a crucial role in monitoring and regulating building functions.

  • Outside Air Sensors: Monitor external temperature conditions.
  • Room Sensors: Installed in various zones to regulate temperature and air quality.
  • Immersion/Duct Sensors: Attached to heating pipes or air handling units to control the heating and cooling systems.


Actuators are mechanical devices attached to systems like heating valves or duct louvers. They adjust the environmental settings by opening and closing valves or adjusting louvers automatically as dictated by the BMS.


Energy meters are integrated to monitor the consumption of utilities such as gas, electricity, and water. Sub-meters may be used to track usage in specific areas, providing detailed insights into the building's energy distribution and highlighting areas for potential savings.

Software Components:

  1. BMS Software:

The software component of a BMS is critical for integrating the data collected from various sensors and executing the control strategies. It enables the processing and analysis of data to ensure that building operations are optimized for energy efficiency and comfort.

Example: Tridium's Niagara Framework integrates various building systems onto a single platform, allowing for centralized data analysis and management.

  1. Controllers:

Within the control panels, controllers hold the strategic logic used to manage the building's systems effectively. These controllers are programmed to respond to the data received from sensors, adjusting the building's systems to maintain optimal conditions automatically.

Example: Distech Controls' programmable controllers execute heating, cooling, and ventilation sequences based on real-time data and predefined schedules.

  1. User Interface:

The user interface allows facility managers and building operators to interact with the system, monitor real-time data, and make adjustments as needed. This interface can be accessed through web-based portals, mobile applications, or directly through physical interfaces on the control panels.

The Honeywell WEBs-N4 software provides a user-friendly interface for facility managers to monitor and control the building’s systems.

Communication Infrastructure:

In the context of a Building Management System (BMS), the network infrastructure refers to the system of connections that allow data to be communicated between the various components of the BMS such as sensors, control panels, actuators, and the user interface.

This network can be either wired or wireless, each having distinct characteristics and applications:

Wired Networks

Wired networks involve physical cables (e.g., Ethernet cables) that connect devices within the BMS. These cables transmit data between sensors, actuators, control panels, and other components.

  • Advantages: Wired networks are generally more reliable and secure than wireless networks. They provide stable connections and are not susceptible to interference from other wireless signals. This makes them ideal for environments where a constant, uninterrupted data flow is critical.
  • Use Cases: In large commercial buildings or complex installations where long-term reliability is paramount, wired networks are often preferred due to their robustness and security features.

Wireless Networks

Wireless networks use radio waves to connect devices within the BMS without the need for physical cables. This includes technologies like Wi-Fi, Zigbee, or Bluetooth.

  • Advantages: The main advantage of wireless networks is flexibility and ease of installation. They eliminate the need for extensive cabling, making them cost-effective and adaptable to changes in building layouts or system expansions.
  • Use Cases: Wireless networks are suitable for smaller buildings or areas where installing physical cables is challenging or disruptive. They are also used in temporary setups or in buildings where aesthetic considerations preclude visible wiring.


Regarding protocols, these are sets of rules that govern how data is transmitted and received over a network. In networking terms, a protocol is a standard or set of rules that devices must follow to communicate effectively over a network. Protocols ensure that data sent by one device is understood correctly by another, regardless of the make or model of the device.

Two protocol examples include: 

BACnet (Building Automation and Control Networks)

A widely used protocol specifically designed for managing building automation and control systems. It supports communication functions among devices such as HVAC units, lighting systems, security systems, and other building services.


Another common protocol used in building management as well as industrial automation systems. It allows for communication on the same network among various devices that monitor and control equipment.

Protocols like BACnet and Modbus define data structure, method of data exchange, and timing for communication. This enables different systems and devices within a BMS to exchange information reliably and interpret it correctly, ensuring seamless operation of building management functions.

Both the choice between wired and wireless networks and the selection of appropriate communication protocols depend on specific building requirements, system complexity, and the need for reliability and security in data handling.

Advantages of Implementing a BMS

Implementing a modern Building Management System (BMS) provides significant advantages that contribute to operational efficiencies, safety, and occupant comfort. Here’s a closer look at how a BMS enhances building management:

  1. Energy Efficiency:

A modern BMS optimizes the operation of mechanical and electrical systems including HVAC, lighting, and power systems. By automating processes such as turning off lights when not needed and adjusting temperature based on occupancy, a BMS can significantly reduce energy consumption and lower energy bills.

For example, smart scheduling and demand-controlled ventilation ensure that energy is used only when necessary, optimizing consumption patterns and significantly reducing waste.

  1. Comfort:

By maintaining controlled indoor environmental conditions—regulating temperature, humidity, and air quality—a BMS ensures a comfortable atmosphere for occupants. Appropriate lighting levels and smooth operation of systems contribute to an environment conducive to productivity and well-being. The system's ability to adapt to varying occupancy and environmental conditions without manual intervention allows for consistent comfort without excessive energy use.

  1. Safety and Emergency Response:

A BMS enhances building safety by integrating fire alarms, smoke detectors, and other emergency response systems into a unified management platform. It can detect and respond to emergencies swiftly, for instance, by controlling emergency exits and directing occupants safely.

Regular monitoring and automatic adjustments reduce risks associated with equipment malfunction, which can lead to accidents or failures.

  1. Reduced Operating Costs:

Through efficient management of building systems, a BMS reduces the costs associated with maintenance and operation. It extends the lifespan of equipment by preventing overuse and facilitating timely maintenance, thereby decreasing the likelihood of costly repairs or replacements. Proactive data analysis and fault detection allow facility managers to address issues before they escalate, ensuring systems operate within their optimal parameters.

With a properly configured BMS, ASHRAE energy audits are easier to perform because all of the data is in one, central location. 

  1. Enhanced Regulatory Compliance:

Modern BMS systems help buildings comply with increasingly stringent energy consumption and emissions regulations. Automated data logging and reporting simplify compliance with environmental standards and building codes.

This compliance is not only beneficial for avoiding penalties but also positions the property as a leader in sustainability, enhancing its market value and appeal.

  1. Improved Asset Management and Security:

The data collected by a BMS provides valuable insights into the performance and utilization of a building’s infrastructure, aiding in effective asset management and decision-making regarding maintenance and capital investments. Organizations attempting to secure ISO 55000 certification, can benefit greatly from implementing a modern BMS.

Enhanced security features of a BMS include controlled access to different building zones and monitoring of security cameras, which help prevent unauthorized access and ensure the safety of the premises.

Challenges and Considerations

While the benefits of a Building Management System (BMS) are considerable, implementing such systems presents certain challenges:

  1. Integration Complexity:

Integrating a BMS with existing building systems can be complex, particularly in older structures not originally designed for centralized management. This integration process requires careful planning to ensure compatibility and functionality across different systems and equipment.

  1. Limited Energy Monitoring and Fault Detection:

Traditional BMS are excellent for controlling building operations but often lack detailed energy monitoring and precise fault detection capabilities. For instance, while a BMS might detect an anomaly like a floor being outside temperature set points, pinpointing the specific malfunctioning unit such as an air handling unit causing that temperature imbalance can be challenging.

  1. Cost Implications:

The initial setup cost of a BMS can be high, especially for comprehensive systems that include advanced features. However, these costs are often offset by the long-term savings in energy and maintenance expenses.

  1. Training Requirements:

Ensuring that staff are adequately trained to use the BMS effectively is essential. Staff must understand how to interpret the system’s outputs and make informed decisions based on real-time data.

  1. Addressing Challenges:

Effective strategies to address these challenges include selecting scalable and flexible BMS solutions that can grow and adapt to the building’s needs. Ensuring vendor support for training and system upgrades can also mitigate these challenges, allowing for smoother operation and maintenance.

Implementing a BMS offers significant potential to enhance the management of building operations, contributing to sustainability, safety, and operational efficiency. While challenges exist, strategic planning and continuous improvement can help maximize the benefits of a BMS.

Future of Building Management Systems

The future of Building Management Systems (BMS) is shaped by advancements in technology, particularly through the integration of the Internet of Things (IoT), Artificial Intelligence (AI), and machine learning. These developments are expected to significantly enhance how buildings are managed and operated:

  1. Integration of IoT
    • IoT expands connectivity across various devices and sensors in a BMS, enabling more granular control and data collection. This leads to optimized energy management and operational efficiency through real-time adjustments based on occupancy and environmental conditions.
  2. Advanced-Data Analytics with AI
    • AI enhances BMS capabilities by providing advanced analytics to identify patterns, predict system failures, and optimize energy usage. This predictive approach not only reduces downtime but also contributes to substantial energy savings and improved equipment longevity.
  3. Machine Learning for Adaptive Learning
    • Machine learning allows BMS to learn from historical data, enabling adaptive system adjustments that enhance HVAC operations and other building functions for better energy efficiency and occupant comfort.
  4. Enhanced User Experience and Control
    • Future BMS will feature more intuitive interfaces, making it easier for users to interact with the system, access performance insights, and manage building operations more effectively.
  5. Greater Emphasis on Security and Privacy
    • As BMS becomes more interconnected, enhancing cybersecurity measures will be crucial to protect data integrity and prevent unauthorized access.
  6. Sustainability and Regulatory Compliance
    • BMS will increasingly support sustainability efforts and regulatory compliance, integrating more closely with renewable energy sources and facilitating carbon footprint monitoring and reporting.

Overall, technological advancements in IoT, AI, and machine learning are set to revolutionize BMS, making them smarter and more proactive in managing building environments efficiently and sustainably. Modern BMS platforms are only the beginning of smart commercial building technologies.

When is BMS a requirement? 

In the United States and the United Kingdom, there is no requirement for having a BMS in a commercial building.

The European Union has mandated the adoption of Building Automation Control Systems (BACS) in tertiary buildings, including hotels, office buildings, towers, and warehouses by January 2025 as part of a move to enhance energy efficiency and cut down CO2 emissions.

This requirement was set in motion in 2020 when EU member countries began integrating this mandate into their own national laws in line with the EU Energy Performance of Buildings Directive (EPBD).

The directive calls for the incorporation or updating of BACS like Building Management Systems in non-residential buildings, both existing and new constructions, if they have an effective rated output exceeding 290 kW.

Cost of a Building Management System

The cost of a Building Management System (BMS) and the selection of the system provider are crucial considerations for any facility manager planning to install or upgrade a BMS. These factors significantly influence both the initial investment and the long-term operational costs of managing a building effectively.

Factors Influencing BMS Costs

  1. Building Size and Type
    • The cost of a BMS typically varies based on the total square footage and the type of building. Larger buildings and those with complex needs, such as data centers requiring extensive cooling, generally incur higher costs.
  2. Integration with Existing Systems
    • The ability to integrate with existing systems like lighting, HVAC, fire safety, security, and access control can affect the initial setup cost. Buildings with comprehensive integrations often see a higher return on investment due to improved operational efficiencies and energy savings.
  3. System Openness
    • Choosing an open, non-proprietary BMS platform can lead to higher ROI as it allows facility managers to integrate various systems and analyze data for energy savings, preventive maintenance, and other performance improvements. Open platforms provide flexibility and can adapt to future technological advancements.
  4. Installation Environment
    • The cost can also differ depending on whether the BMS is being installed in a new building, retrofitted into an older building, or upgraded from a legacy system. New installations in new constructions are usually less expensive compared to retrofitting an old system due to the absence of legacy system complications.

Estimated Cost Range

The BMS cost per square meter typically ranges from $2.50 to $7.50, influenced by the specific requirements and features implemented. This pricing can fluctuate based on the complexity of the system and the specific needs of the business.

As a rule, if your building is larger than 50,000 square feet, the cost to install a BMS will be offset by the associated efficiency gains.

Major Building Management System Companies

The BMS industry is dominated by several major players known for their innovative solutions and global reach. Here’s a brief overview of some of the top companies in this space:


Headquartered in the US, Cisco specializes in networking hardware, telecommunications equipment, and high-technology services and products, including smart building solutions through its Digital Building Solution. This solution optimizes building operations using IoT technology. Learn more about Cisco


Based in the US, Honeywell has a diverse range of commercial and consumer products and services. It offers extensive BMS capabilities, including automation systems, software, and controls, focusing on energy savings and operational efficiencies. Honeywell also owns Trend Control Systems, a prominent BMS provider in the UK and Ireland. Learn more about Honeywell

Johnson Controls

Originally founded in Ireland, Johnson Controls manufactures a wide range of products for buildings, including electronics and HVAC equipment. Its Metasys Building Automation System is noted for contributing to global energy management trends. Learn more about Johnson Controls

Schneider Electric

Founded in France, Schneider Electric offers products for electricity distribution, energy management, and building automation. The company is known for its EcoStruxure Building platform, which supports IoT connectivity to enhance building operations. Learn more about Schneider Electric


A German conglomerate, Siemens provides a wide array of services and products across multiple industries, including building technologies. Their BMS solutions include the Desigo, Synco, and GAMMA product lines, designed for efficient building automation and control.

Learn more about Siemens


Headquartered in the US, Emerson offers engineering services and products for various markets, including commercial and residential solutions. Their supervisory control systems provide advanced facilities management capabilities. Learn more about Emerson

United Technologies

Based in the US, United Technologies manufactures products for the aerospace and building systems industries, among others. Its dedicated segment, UTC Climate, Controls & Security, focuses on high-tech building solutions. Learn more about United Technologies


A German engineering and electronics firm, Bosch's Building Integration System (BIS) manages various security subsystems on a single platform, enhancing building safety and operational efficiency. Learn more about Bosch

Bajaj Electricals

An Indian company known for its electrical equipment and lighting, Bajaj Electricals entered the BMS market with solutions focusing on integrated building management for enhanced operational control and energy management. Learn more about Bajaj Electricals

Building Logix

Building Logix provides a comprehensive range of BMS solutions, from access and video control to energy management and system integration. They focus on leveraging existing infrastructures to enhance building performance. Learn more about Building Logix

These companies lead the way in developing and deploying building management systems that enhance energy efficiency, ensure safety, and improve the overall management of building operations globally.

Conclusion: The Evolution of Building Management to Building Analytics

As commercial buildings continue to evolve into increasingly complex systems, the role of a Building Management System (BMS) is foundational but just the first step towards achieving comprehensive building intelligence. While a BMS efficiently integrates and manages the various subsystems within a building, establishing a single view of all connected endpoints, the next phase of building evolution extends into more nuanced energy management and operational efficiency through Building Energy Management Systems (BEMS) or building analytics platforms, such as CIM's PEAK Platform.

For a graphical representation of how PEAK works on top of your BMS system, see the below diagram:

How Building Analytics Ingest your BMS Data and Other Sources

First, PEAK collects data from your water company, utility company, BMS provider, etc. Next the platform uses that information to identify mechanical faults within your building, allowing you to assign tickets to your onsite facility management team and ensure your building is running at its most efficient.

CIM connects to your BMS via a RJ45 cable. Using a Bacer, PEAK connects to your onsite network and pulls your building's operational information into our AI-drive software platform. In a matter of days, the platform can be up and running, identifying the inevitable faults and failures that occur in your building.

Integrating CIM's PEAK Platform with a BMS:

CIM’s PEAK Platform exemplifies the advancement in building analytics that modern facilities require. It harnesses the data collected by a traditional BMS and elevates it through sophisticated analysis and interpretation techniques. This approach unlocks critical insights that go beyond the surface-level data, providing deep dives into energy consumption patterns, operational anomalies, and predictive maintenance cues.

Predictive Maintenance and Operational Efficiency:

One of the standout features of building analytics platforms is predictive maintenance. By predicting potential system failures before they occur, the PEAK Platform helps avoid unplanned downtime and expensive repairs, while also ensuring that the building’s systems are running at peak efficiency. This proactive maintenance strategy not only extends the lifespan of the building's infrastructure but also enhances overall energy efficiency.

In conclusion, while a BMS is crucial for the fundamental management of building systems, the future lies in building analytics platforms like CIM’s PEAK Platform. These advanced systems represent a significant leap forward in building management, offering the tools to transform data into actionable insights that drive efficiency, reduce costs, and improve the sustainability of building operations. As buildings continue to evolve, the integration of these advanced analytics platforms will become increasingly essential in managing the modern, smart buildings of tomorrow.

Connor Holbert
April 26, 2024