In January 2021 the International Code Council published the 2021 version of the International Energy Conservation Code (IECC). This new version reduces lighting power allowances as well as expanding upon mandatory controls requirements.

Below is a brief summary of the most significant changes:

Occupancy Sensing

Corridors are now listed as one of the applications requiring occupancy sensors and have their own section with specific requirements.

Daylight Harvesting

IECC 2021 now identifies secondary daylit zones. The update also recognizes a rooftop monitor as producing sidelit illumination. The code recognizes projection factor (shading by overhanging projections) as potentially limiting the utility of implementing daylight-responsive control. Finally, daylight zones in atrium spaces must be established at the top floor surrounding the atrium and not any intermediate floors.

Daylight Responsive Controls

The continuous dimming to at least 15% of full output or lower is now required in all zones with daylight-responsive control. In warehouses, open offices, and corridors where occupancy sensing produces a light-reduction effect, daylight-responsive controls may reduce power further but not raise it above the level set by the occupancy sensor.

Parking Garage Lighting Controls

Completely new to IECC, parking garage lighting must be controlled by either an occupancy sensor or a time-switch control function. Additionally, lighting power must be automatically reduced based on occupancy with a time delay of 20 minutes and a control zone limited to a maximum of 3,600 SQFT At entrances and exits where light affects eye adaptation between indoor and outdoor brightness levels, lighting must be reduced by at least 50% between sunset to sunrise.

Plug Load Controls

IECC 2021 now contains new general receptacle control requirements. At least 50% of all permanently installed 15A and 20A receptacles installed in certain applications (such as enclosed offices, workstations, and classrooms) must be controlled. At least 25% of branch circuit feeders installed for modular furniture must also be controlled. The control function may be based on split-controlled receptacles (top controlled) or separate controlled receptacles must be installed within 1’-0” of each uncontrolled receptacle. All controlled receptacles must be marked per NFPA 70 and uniformly distributed. The receptacles may be controlled either on a scheduled basis using a time-switch control function, via an occupancy sensor with a 20-minute time delay, or via a signal from another control, security, or alarm system.

Exterior Lighting Controls

Dusk-to-dawn lighting power must be reduced by at least 50% after-hours. Outdoor parking lot luminaires greater than 78W and with a mounting height of 42 feet or less must be controlled with an occupancy sensor that reduces power by at least 50% with a 15-minute time delay. For control of such luminaires, control zoning is limited to 1500W of lighting power. Refer to the local authority having jurisdiction and also local amendments for additional requirements.

This resource has been prepared by Steph Powell, Senior Lighting Designer at AE Design

2021 IECC Updates