What Is the Measure?
Effective building operation is critical to achieving long-term energy cost savings, sustainability goals, and compliance with evolving performance standards. This measure focuses on the design and installation of Building Management Systems (BMS) and Energy Management Systems (EMS) for small to mid-sized nonresidential buildings (generally 5,000-50,000 square feet). A BMS or EMS centrally monitors, controls, and optimizes building systems—most commonly HVAC, lighting, and service hot water. When correctly leveraged, BMS and EMS can provide significant operational improvements to deliver meaningful energy and performance benefits.
A BMS traditionally focuses on real-time control of building systems to maintain occupant comfort and proper equipment operation, while an EMS emphasizes energy tracking, analysis, and optimization over longer timeframes. Control capabilities enable efficient day-to-day operation, while energy-focused features support performance benchmarking, load management, and participation in demand response or other grid-interactive programs. For the purposes of this measure, BMS and EMS are treated as complementary components of a unified building control and energy management strategy.
Key Components
While system architecture and capabilities vary by project, BMS/EMS installations typically include the following functional components:
- Field devices and sensors, such as temperature, flow, pressure, or status sensors, that collect real-time operating data from building systems.
- Controllers, including programmable thermostats, unit controllers, or direct digital control devices, that execute control logic at the equipment or zone level.
- Supervisory or management-level software, which provides centralized scheduling, monitoring, trending, and alarm functionality through a local or web-based interface.
- Communication networks and open protocols, often using open standards such as BACnet or Modbus, to enable data exchange between devices and systems.
- Data storage and visualization tools, which allow operators to review trends, identify faults, and evaluate system performance over time.
The level of sophistication may range from entry-level centralized monitoring and scheduling to advanced systems with analytics, fault detection, and automated demand response capabilities, depending on project scope and design objectives.
How it Works
In a BMS/EMS installation, field devices, controllers, and supervisory software work together to monitor building conditions and manage system operation. At the field level, sensors installed on equipment and in occupied spaces measure parameters such as temperature, flow, pressure, and equipment status. This data is transmitted through communication networks using open protocols—commonly BACnet or Modbus—to local or networked controllers.
Controllers use programmed control logic to operate HVAC equipment, lighting systems, and other connected loads based on schedules, setpoints, and real operating conditions. Supervisory or management-level software aggregates information from multiple controllers and systems into a centralized interface. At this level, operators can view system status, adjust schedules, modify setpoints, respond to alarms, and coordinate across multiple systems.
Centralized control helps avoid conflicting operation, such as simultaneous heating and cooling or equipment running during unoccupied periods. Depending on system design, this supervisory layer may be hosted locally, accessed through a web-based interface, or integrated with cloud-based services. In more advanced configurations, collected data can also be used to support energy analysis, demand response actions, or reporting for program or code-readiness purposes.
When to Consider This Measure
Operational conditions are important to evaluate when considering whether a BMS/EMS approach is a good fit. Benefits are often greatest in buildings with variable occupancy, extended operating hours, diverse load profiles, or frequent schedule changes. Buildings with multiple HVAC units, zoned systems, or shared mechanical equipment are more likely to experience inefficiencies related to manual control or limited visibility into system performance. In these cases, centralized scheduling and coordinated control can support more stable and efficient operation over time.
BMS/EMS platforms are generally most cost-effective when implemented as part of new construction or a major renovation, where communication infrastructure can be incorporated early in the design process. Early coordination reduces the need for later modifications and helps ensure that control strategies, sensor placement, and system integration are planned holistically. Retrofit projects may also be good candidates, particularly where existing buildings rely on standalone thermostats or limited control strategies. However, retrofits may face constraints related to legacy equipment, limited access to control points, or physical space for controllers and networking. In those cases, phased implementations can be a practical approach, prioritizing high-impact systems first and expanding functionality over time as feasible.
Equipment Selection Considerations
When selecting BMS/EMS equipment, compatibility with the building’s mechanical systems is a primary consideration. The controls platform should be capable of integrating with the types of HVAC equipment on the project and supporting the necessary control sequences and monitoring functions. Projects should also consider the required level of control at the equipment or zone level. In some applications, centrally connected programmable thermostats may be sufficient; in others full direct digital control with point-level access may be needed.
Although it is important to size the BMS/EMS for the current needs of the building, it is also important to consider any potential future expansions helping avoid the need to replace or upgrade the system. Open communication protocols such as BACnet or Modbus allow for this flexibility through supporting interoperability across manufacturers and reduces reliance on proprietary gateways.
Because BMS/EMS platforms rely on network connectivity for centralized monitoring and remote access, cybersecurity is an important aspect to ensuring these systems are operating efficiently. Ensuring access is granted on role-based permissions can help limit unauthorized changes to system operation. Network segmentation, firewall protection, encrypted connections where appropriate, and regular software updates can also help maintain system security over time.
System Configurations
The figure above illustrates a representative BMS/EMS outline organized in layers. Field-level equipment—such as air handling units, boilers, chillers, and terminal units—connects to local controllers, which manage equipment operation. These controllers communicate with plant and interface controllers, which coordinate multiple systems and integrate additional building functions such as fire alarm, metering, access control and vertical transportation.
At the supervisory level, a BMS/EMS server provides centralized monitoring, trending, and control. Network protection functions such as firewalls and segmentation support secure connectivity, while optional cloud services may enable remote access and advanced analytics.
This diagram reflects a typical control hierarchy and data flow; actual configurations will vary based on building size, complexity, and project goals. It’s recommended to work with a qualified professional to determine the optimal configuration for your building.
Pairing Considerations
BMS/EMS pairs particularly well with high-efficiency HVAC and heat pump systems, including air-to-air, air-to-water, and water-to-water heat pumps. When integrated, the controls system can manage scheduling, setpoint resets, staging, and load balancing to improve efficiency and reduce peak demand.
Ventilation and air distribution systems, such as Dedicated Outdoor Air Systems (DOAS) and Variable Air Volume (VAV), benefit from coordinated airflow and scheduling. Domestic hot water and heat recovery systems—including heat pump water heaters and wastewater or refrigeration heat recovery—can be optimized through coordinated monitoring and staging that optimizes recovered heat use relative to other building loads.
Buildings with electrified heating or thermal storage can leverage BMS/EMS to support demand response participation and other grid-interactive operation without manual intervention.
Cost Considerations
Upfront costs vary depending on system scope, integration level, and building complexity. Initial costs may include controls hardware, sensors, controllers, networking infrastructure, software licenses, system integration, and commissioning. Projects that integrate multiple systems or require extensive retrofitting of existing equipment may see higher upfront costs than those incorporating BMS/EMS as part of new construction or major system upgrades
Ongoing costs typically include software support, cybersecurity updates, sensor calibration, and staff time to review system data and respond to alarms. When properly implemented and actively used, operational savings, reduced equipment wear, and improved system reliability can offset these costs over time.
What Are the Benefits?
- Provides granular, time-resolved energy and operational data to support benchmarking, performance verification, and ongoing optimization.
- Enhances operational efficiency by centralizing system monitoring, scheduling, and control within a single platform, reducing reliance on manual adjustments and standalone controls.
- Supports grid-interactive building strategies, including automated demand response and load management strategies where capabilities are included.
- Aligns system operation with occupancy, schedules, and real operating conditions, reducing unnecessary runtime during low-demand periods.
- Improves maintenance planning and can reduce avoidable equipment wear, supporting longer asset life and consistent occupant comfort.
What Are the Challenges/Constraints?
- Requires upfront investment in controls, sensors, integration, and commissioning.
- Relies on thoughtful system design and proper configuration to ensure that expected performance outcomes are achieved for site-specific needs.
- Effective operation depends on staff familiarity and engagement; without basic training and ongoing attention, system capabilities may be underutilized.
- May face integration challenges in existing buildings due to legacy equipment or limited access to control points.
- Requires ongoing maintenance, calibration, and periodic updates to sustain performance as building conditions evolve.
What Are the Qualifications for CEDA Inducements?
To be eligible for CEDA inducements under the BMS/EMS High-Performance Measure, a project must:
- Be located within the service territory of SCE, SoCalGas, PG&E or SDG&E.
- Be enrolled in the CEDA program and meet all standard program participation requirements.
- Implement a qualifying BMS/EMS tier (Essential, Advanced, or Premium) and submit the required supporting documentation.
- Implement at least one additional qualifying CEDA High-Performance Measure (see CaliforniaEDA.com/high-performance-measures).
- Provide design and equipment documentation consistent with the permitted documents set for the project (e.g., equipment schedules or submittals reviewed and approved by the Engineer of Record, sequences of operation, and control/points information as applicable).
- Participate in on-site verification.
- Participate in equipment data collection effort if selected.
Notes:
- Project may be selected by PG&E for a future case study.
- Measure requirements are subject to change; this guide reflects information available as of March 2026—for the most current measure requirements, contact CEDA@willdan.com.
References
- Chartered Institution of Building Services Engineers (CIBSE). (n.d.). Introduction to Building Management Systems. Building Management Systems.pdf
- EarthCheck. (n.d.). Fact Sheet: Building Management Systems. EarthCheck. Fact Sheet: Building Management Systems.pdf
- Siemens Industry, Inc. (2024). Building Automation System Basics. Engineering Advantage Program. Building Automation System Basics.pdf
- Willdan. (2026). CEDA High-Performance Measure: Building Management Systems (BMS) and Energy Management Systems (EMS). California Energy Design Assistance Program (CEDA). CEDA High-Performance Measure: Building Management Systems (BMS) and Energy Management Systems (EMS).pdf
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