Clint’s Controls Corner: IECC 2018 Changes


Clint's Controls Corner (text only)

The International Code Council has now released the 2018 edition of the International Energy Conservation Code (IECC). At this time, no jurisdiction in Colorado has changed over to this code as far as I am aware, but it is coming. The State of Colorado will adopt this code for all state funded projects on July 1, 2019. 

Changes in this code from the 2015 version are not as extensive as what we saw in the update from the 2012 code to the 2015 version. Much of the 2018 version remains the same as the 2015 version, with some wording updates intended to make interpretation more clear. However, some of these wording updates may have unintended consequences.

In general, it is apparent that the energy code is evolving towards more occupancy sensor-based and less time-based automatic controls. In particular, there is now specific mention of fixture-based lighting controls in multiple sections of the code, including a section allowing optional compliance using “Luminaire Level Lighting Control.” To comply with the requirements in this section, a wireless, intelligent lighting control system in fixtures with dimming and integrated occupancy and daylight sensors will be required.   

With this new code, I had expected that we would see the IECC follow ASHRAE requirements for automatic receptacle shutoff based on room occupancy. This requirement is not included in the 2018 version of the IECC.

In the changes to this version of the code, new requirements for open plan office areas and accent and display lighting are the most significant. Additionally, the requirements for remodel work have been changed to mandate that any new lighting system must comply with lighting control requirements; the only exception being when less than 10% of the luminaries will be replaced. For remodel and retrofit work, controls will have to be upgraded for most projects under this requirement.

Open Plan Office Areas
These spaces are now required to have occupancy sensor-based lighting controls (in previous versions of the code, time-based control from lighting control panels was allowed). Additionally, there must be a control zone for every 600 square feet of floor space. For large, open plan offices, this will quickly add up to a lot of control zones. Manual-on (vacancy sensing) operation is also required which can only be accomplished with low voltage switches to turn the lights on, and limits the ability to use simple fixture based controls.

In order to minimize the inconsistent ceiling appearance when some zones are illuminated and others are not, it is allowed for the unoccupied zones to reduce light by 80% rather than turn completely off. However, the entire space must turn completely off 20 minutes after the last occupant leaves the area. To accomplish this functionality, all control zones will need to be interconnected with an advanced system capable of being programmed to operate small zones independently, and then communicate so that when all zones are vacant, the lights turn completely off.

For large areas, these requirements will most easily be met using fixture integrated controls. Using room controllers and/or relays would require a great amount of wiring, and would require a large number of sensors to be installed on the ceiling. Using an intelligent system that has fixture integrated sensors and the ability for fixtures to communicate from fixture to fixture will be the most effective solution for these spaces.

Accent and Display Lighting
In the 2015 version of the IECC, these areas were required to be controlled separately from general lighting. In the 2018 version, this lighting is also required to have automatic (occupancy-based or time-based) control. To meet this requirement, additional relays or room controllers will be required for the specialty lighting. Lighting in this category includes: under-cabinet lighting, display and accent lighting, supplemental task lighting, display cases, food warming, and plant growth lighting. 

Of particular note in the above list is the supplemental task lighting. This will be another impact to open plan offices. In spaces where cubicles with task lighting are used, a strategy will need to be implemented to automatically turn off all task lighting which is typically plugged in to receptacles installed in the cubicles. To meet this requirement, all task lights will either need to be on the same controlled circuit, or occupancy sensors will be needed at each desk or fixture.

The above items are not all of the changes in the new code, but they are the ones that will have the most impact to lighting controls design, as well as the overall cost of lighting control solutions. As the codes and technology continue to evolve, it is clear that we are headed towards fixture integrated lighting controls.

Contact the controls team at MH anytime for any lighting control code or other question. We are happy to present the in-depth requirements and discuss the impacts to project design. Additionally, Legrand has created some helpful cheat sheets for IECC and ASHRAE compliance. They can be found at under the “Quick Guides” section.

This article was written by Clint Conley, our Lighting Controls Department Manager. Clint can be reached at 720.904.8554 or