MH Controls Corner: 2015 IECC Code Summary

The following is intended to be a brief overview of the requirements of the 2015 IECC as they relate to lighting control systems. Please review the text of the code before applying any of these guidelines as there are exceptions and details that are not included in this summary.

General Guidelines (exceptions may apply):

• Occupant sensor controls required in most spaces. The code now lists space types where sensors are required.
• Manual on and off controls are required (vacancy mode). Occupant controlled lighting can be auto-on to 50% only. In all cases manual off is required (even in restrooms).
• Time control is required where occupant control is not. There must be at least one override switch for every 5,000 square feet. Manual light reduction control is also required in spaces with time based control.
• Where there are windows or skylights, automatic daylight harvesting is required. The code now includes very prescriptive guidance for the required size of daylight zones. If there is less than 150 watts of lighting in the daylight zone, automatic daylighting is not required.
• Exterior lighting has to be capable of load reduction by at least 30% based on time or occupancy.
• All new buildings in jurisdictions that adopt this code will have to comply. There is no longer an exclusion for buildings smaller than 5,000 square feet.
• The registered design professional is required to certify that the installed system operates as intended by the construction documents.

Detailed Guidelines (additional exceptions may apply):

• Occupant sensor control requirements are listed by space type.
  • Lighting is required to be manual on or auto on to 50% only.
  • Full auto on is allowed in corridors, entrances, and other similar spaces.
  • A manual control to turn lights off is required.
  • Dwelling units in commercial buildings do not have to meet these requirements.
• Where occupant sensors are not used, time control is required:
  • Applies to open offices and other spaces.
  • Override switches are required.
    • Not more than 2 hours override.
    • Override switches are required for every 5,000 square feet.
  • Each space with time control is required to also have a manual light reduction control.
    • If an automatic daylight harvesting system is present the manual control is not required.
• Automatic daylight harvesting:
  • Must be able to be calibrated without the use of a ladder.
  • There are specific requirements for the size of the daylight zone.
  • In classrooms, offices, laboratories, and library reading rooms, daylighting requires continuous dimming to 15%.
  • Daylighting has to be capable of shutting off all controlled lights.
• Display and accent lighting are required to have control separate from other fixtures in the space.
• Hotel and motel sleeping rooms require a master control device that will automatically shut off all lights and receptacles within 20 minutes of the occupant leaving the room.
• Exterior lighting controls:
  • Lights must be provided with a control that will turn off lights based on available daylight.
  • Lighting shall have controls configured to automatically reduce lighting load by 30% from midnight to 6am, from one hour after business closing to one hour before business open, OR during any period when activity has not been detected for a time longer than 15 minutes (note the “or” in this criteria). There is an additional benefit to having continuous dimming with a digital, addressable control system (under additional efficiency package options).