Energy codes for commercial buildings are not the most exciting reading material, but the requirements they contain have a direct impact on what controls you are legally required to install in new construction and major renovations. The 2024 edition of the International Energy Conservation Code includes several updates to building controls requirements that are worth understanding before your next project goes to permit.
This post focuses on the commercial provisions of the 2024 IECC and their relationship to ASHRAE 90.1-2022, which the 2024 IECC references for many of its commercial building requirements. We will also discuss Louisiana-specific adoption context, because energy code adoption in Louisiana has its own timeline that does not always align with the federal adoption cycle.
The Relationship Between IECC and ASHRAE 90.1
Before diving into specific changes, it is worth clarifying how these two documents relate. The IECC is a model code published by the International Code Council. For commercial buildings, the 2024 IECC adopts ASHRAE 90.1-2022 by reference for most energy efficiency requirements. This means in jurisdictions that have adopted the 2024 IECC, commercial buildings are effectively required to comply with ASHRAE 90.1-2022.
ASHRAE 90.1 covers the full spectrum of commercial building energy: envelope, lighting, mechanical systems, and service water heating. The controls requirements we are focused on here primarily fall under the mechanical and electrical sections.
Expanded HVAC Controls Requirements
Fault Detection and Diagnostics
One of the more significant changes in ASHRAE 90.1-2022 is the expanded requirement for automated fault detection and diagnostics (FDD). Under 90.1-2022:
- Air-handling units larger than 5,000 CFM must be equipped with automated FDD systems that continuously monitor operation and provide alerts for common fault conditions including sensor failures, economizer faults, and refrigerant charge issues.
- Packaged unitary equipment above certain size thresholds is subject to FDD requirements as well.
FDD requirements push toward active monitoring rather than passive data collection. The system must not only detect fault conditions but must generate actionable alerts that prompt investigation. This represents a meaningful shift from earlier code editions that simply required controls to implement certain strategies, without requiring those controls to verify that the strategies were actually working.
For new construction, FDD capability is increasingly a feature built into major equipment at the factory. For retrofit applications, third-party FDD platforms that integrate with existing BAS data can satisfy the requirement. Either way, this is now code, not optional.
Enhanced Economizer Controls
Economizer requirements have been progressively tightened over successive code editions, and 90.1-2022 continues that trend. Key changes include:
- Economizer high-limit shutoff controls must be set based on enthalpy or dewpoint comparison, not just dry-bulb temperature, in climate zones where enthalpy-based control provides measurably better energy performance. This affects how economizer sequences are programmed and commissioned.
- Economizer compliance verification is now more explicitly tied to commissioning and functional testing requirements. You cannot simply install an economizer damper and call it compliant. The controls sequence must be tested and documented.
For Louisiana, which sits in ASHRAE climate zone 2A (hot-humid), economizer hours are limited to begin with. However, the controls requirements still apply to systems that include economizers, and the sequencing must meet the code requirements for the climate zone.
Demand-Controlled Ventilation Expansion
The 2024 IECC and 90.1-2022 expand demand-controlled ventilation (DCV) requirements to cover more spaces and more system types. DCV is now required in:
- Spaces larger than 500 square feet with design occupancies above 25 people per 1,000 square feet, served by systems with design outside air capacity above 3,000 CFM (the thresholds were tightened from previous editions)
- Retail spaces above certain sizes
- Additional occupancy categories that were not covered under earlier versions
If your new building includes conference rooms, classrooms, assembly spaces, or retail areas served by central air handling systems, DCV is very likely required.
Building Performance Monitoring Requirements
90.1-2022 includes new provisions for energy monitoring and reporting in larger commercial buildings. Buildings above 25,000 square feet are subject to requirements for:
- Electrical energy metering at the building level, with submetering for HVAC, lighting, and plug load categories above certain thresholds
- Data recording and storage of energy consumption data at intervals of no more than 15 minutes, retained for a minimum of 2 years
- System-level trending for major HVAC equipment to support ongoing commissioning and energy management
These requirements push building automation systems toward more comprehensive data collection and longer data retention than many systems have been configured for historically. A Niagara N4 system with properly configured trend logging and an adequate historian meets these requirements naturally. A system with default trend settings and 30-day data retention may not.
Updated Lighting Controls and Lighting Power Density
Lighting power density limits in 90.1-2022 are more stringent than previous editions across virtually all space types. The controls requirements tied to lighting include:
- Automatic shutoff controls for all indoor spaces, with more specific requirements for daylight zone controls near perimeter windows and skylights
- Occupancy sensing in a wider range of space types, with specific requirements for sensor placement and time delay settings
- Daylight responsive controls (dimming in response to available daylight) in primary sidelighted and toplighted zones above certain daylight zone area thresholds
For BAS integration, the relevant question is whether lighting controls will be integrated into the main building automation system or implemented as a standalone lighting control system. The code does not require integration, but an integrated approach offers advantages for coordinated scheduling, demand response, and energy reporting.
What These Changes Mean for Your Project
If you are planning new construction or a major renovation, the threshold that typically triggers full code compliance is a renovation involving the HVAC system serving more than 50% of the building area, or any addition over 10,000 square feet.
From a practical standpoint, the 2024 IECC and 90.1-2022 requirements mean:
- Your BAS specification needs to explicitly include FDD capabilities for large air handlers
- Economizer sequences need to be written to current enthalpy-based logic requirements and verified through commissioning
- DCV needs to be included in the mechanical and controls design for qualifying spaces from the beginning of design, not added as an afterthought
- Your energy metering and trending strategy needs to be planned at the design stage to meet monitoring and reporting requirements
Louisiana Adoption Context
Louisiana adopts the IECC on its own schedule through the Louisiana State Uniform Construction Code Council. As of 2025, Louisiana commercial buildings are subject to a version of the IECC that lags the current published edition by one to two cycles in some jurisdictions, and local amendments may modify specific requirements.
Before designing to the 2024 IECC, confirm with your architect or engineer of record which code edition and which amendments apply to your specific jurisdiction and project type. The Louisiana State Fire Marshal's office and local building departments are the authority having jurisdiction for most commercial projects.
What we can say with confidence: even if your jurisdiction has not yet adopted the 2024 IECC, the trajectory of energy code requirements is consistently toward more controls, more monitoring, and more verification. Designing to current best practice now means your building will not be obsolete the next time the code updates.