The Lighting Controls Academy’s Craig DiLouie interviewed Levin Nock, PhD, Senior Technical Manager, DesignLights Consortium (DLC) about the release of the DLC’s Networked Lighting Controls (NLC) Technical Requirements V5.2. Here’s the transcript.
DiLouie: How does DLC see the overall rebate opportunity for commercial lighting, including NLC systems?
Nock: The DLC sees a strong continuing rebate opportunity for commercial lighting, but the center of gravity is shifting. Historically, commercial lighting incentives have focused on simple lamp and fixture upgrades with little or no controls. Due to the success of incentive programs to date, savings from “lighting-only” retrofits are smaller due to a baseline that is often LED.
The DLC sees networked lighting controls — especially luminaire level lighting controls (LLLC), and systems that integrate with other building control systems — as a major pathway for ongoing commercial lighting incentives and rebates. The NLC Qualified Products List (QPL) already plays a significant role in rebate programs. Nearly 100 NLC systems are eligible for incentives and rebates across 46 U.S. states and three Canadian provinces. In 31 of those markets, utilities restrict incentives to NLC systems that have been qualified by the DLC (i.e., DLC-listed).
DiLouie: How does the DLC define networked lighting controls, and why is this technology a core focus for a QPL? What is the energy savings potential?
Nock: For the purposes of the NLC Technical Requirements, the DLC defines a networked lighting control system as a collection of interconnected devices that enable lighting control strategies such as individual addressability, continuous dimming, high-end trim, occupancy sensing, daylight harvesting, scene control, scheduling, energy monitoring, and integration with other systems.
This technology is a core focus for a QPL because NLC systems are complex and difficult to compare without a common framework. An NLC system includes software, sensors, controllers, user interfaces, networking, cybersecurity, configuration practices, and integration capabilities. The QPL gives utilities, program administrators, specifiers, contractors, and building owners a structured way to identify systems that meet baseline requirements and compare reported capabilities.
The best time to install NLC is when fixtures are being replaced in a lighting retrofit. The project will save energy with (a) higher efficacy fixtures, (b) LLLC, and sometimes also (c) by delivering occupancy data to the HVAC control system. Higher-efficacy fixtures can save half of the old lighting wattage in market segments such as small business, rural, and low income where many facilities have yet to be upgraded to LED. In facilities with old LEDs, an upgrade to new LEDs typically saves 10% to 15% of the old lighting wattage. And then, LLLC will save, on average, 63% of the new lighting load.
Most data about energy savings in buildings with variable occupancy and suitable HVAC design comes from large buildings with custom-programmed Building Management Systems (BMS). In small buildings without BMS, early results suggest that occupancy data from an LLLC system may save up to 11% of cooling energy and up to 21% of heating energy in a well maintained building. If the existing thermostat was not already programmed well to match the building’s schedule, HVAC savings will be even higher. More data from small buildings will become available over the next few years from new projects, which will support better estimates of the savings potential. In some buildings, lighting retrofits will deliver more energy savings from occupancy-controlled HVAC than from lighting. Depending on the type of heat source, some projects will save heating fuel in addition to electricity.
DiLouie: What was the purpose of the original NLC Technical Requirements, and what has been accomplished?
Nock: The original 2016 NLC Technical Requirements created a credible, unified performance specification for networked lighting control systems to support a Qualified Products List (QPL) and help energy efficiency programs promote this energy-saving technology into broader deployment. The requirements addressed early market barriers such as inadequate performance data, lack of performance requirements, limited standardization, inadequate documentation, and difficulty comparing complex control systems. The requirements gave efficiency programs a structured way to understand, evaluate, compare, and qualify advanced lighting control products for incentives and rebates, while also giving manufacturers clearer expectations for product capabilities and performance.
Today, nearly 100 NLC systems are eligible for incentives and rebates across 46 U.S. states and three Canadian provinces. In 31 of those markets, utilities restrict incentives to NLC systems that have been qualified by the DLC (i.e., DLC-listed). The DLC has helped several control capabilities to become common practice including continuous dimming, cybersecurity certification, digital networking, individual addressability and sufficient documentation.
Energy efficiency programs that mainly incentivized uncontrolled lighting retrofits in the past have recently been shifting their focus to lighting controls, so that lighting retrofits can continue to deliver energy savings. For example, in 2022, only 4% of linear fixtures sold through the Rhode Island Energy midstream program included Luminaire Level Lighting Controls (LLLC), whereas today the number is 75%.
DiLouie: What changed in NLC 5.1 and then in NLC 5.2?
Nock: Moving from NLC 4.0 to 5.0 was a big jump, with a new mandatory requirement for cybersecurity certification. On a smaller scale, NLC 5.1 adjusted some cybersecurity details, added a new section on NLC Primary Use Designations, and changed the words “Interior” and “Exterior” to “Indoor” and “Outdoor” to align with other DLC documents.
The main changes for NLC 5.2 are that the NLC Technical Requirements now recognize NLC systems that support easy thermostat integration for digital occupancy control and systems that can generate ANSI/NEMA C137.9 configuration reports. Both of these new capabilities are “Reported” (i.e., optional), not “Required” (i.e., mandatory). Associated with the changes in the Technical Requirements, we’re also updating the QPL, so that LLLC systems on the DLC NLC QPL will now be directly associated with one or more LLLC luminaires or kits listed under SSL V6.0 on the DLC SSL QPL.
In addition, language was updated to accept all systems that meet all the NLC requirements, even if a system also supports horticultural control. The document format was updated to consolidate capability descriptions; the term “Primary Use Designation” was changed to “System Scope” to align the NLC Technical Requirements with the NLC QPL; and a reference to ANSI NEMA C137.5 was added to the Energy Monitoring recommendations. In Tables 2 and 3, the capability called “Type of User Interface” was moved from Reported to Required, to align with the longstanding application process. A description of the type of user interface has always been required in every application.
These updates reinforce the role of networked lighting controls as a foundation for integrated building controls and deeper energy savings and decarbonization across building systems. V5.2 encourages opportunities for NLC-HVAC integration, supports greater consistency in configuration reporting, improves alignment between NLC and SSL product information, and helps make the QPL more useful for efficiency programs, manufacturers, specifiers, and building owners.
DiLouie: Why did the DLC decide to initiate changes to produce NLC 5.2?
Nock: Many energy efficiency program managers are eager to capture deeper energy savings from lighting retrofits by including smart thermostats that use occupancy data from networked lighting control sensors to save HVAC energy in spaces without dedicated Building Management Systems or regularly updated scheduling. These thermostats show promise to save energy in small commercial buildings such as schools and retail that have historically been difficult for efficiency programs to serve. In addition, saving HVAC energy supports organizational and regional decarbonization goals, especially for buildings heated by fossil fuels.
Efficiency program managers also look forward to using the new ANSI/NEMA C137.9 standard for NLC configuration reports to reduce their administrative burden while scaling up support for lighting retrofits. These reports will give programs confidence that NLC systems are configured appropriately to deliver energy savings, thereby justifying the incentive program investments. These are the two main opportunities opened up by NLC 5.2.
DiLouie: What was the process the DLC undertook to develop NLC 5.2? When does it become effective, and how will this impact current QPL listings?
Nock: The DLC developed NLC V5.2 through a stakeholder process focused primarily on two emerging opportunities: standardized configuration reporting and NLC-to-thermostat integration. For the thermostat portion, DLC convened a working group in early 2026 with DLC members, NLC and lighting manufacturers, thermostat manufacturers, standards bodies, implementation perspectives, and other stakeholders. DLC included additional NLC manufacturers in the development process through the NEMA Lighting Controls Technical Committee. The purpose was to help define practical, technology-agnostic requirements for recognizing thermostats that can be easily integrated with NLC systems.
The DLC then released Draft 1 on March 30, 2026, held a draft-release webinar on April 8, and ran a six-week public comment period from March 30 through May 8. DLC received 46 comments from ten organizations, including controls manufacturers, luminaire/control manufacturers, HVAC controls manufacturers, implementers, and industry organizations. Commenters were generally supportive of recognizing NLC-HVAC integration, while asking DLC to make the requirements clearer, more flexible, more reflective of real-world installations, and optional at this early point in the development of new capabilities. DLC revised the requirements from May 8 through June 22, then released the final NLC V5.2 requirements on June 23, 2026.
NLC V5.2 takes effect on August 3, 2026. Based on the nature of the changes, the update is not expected to cause delistings of current QPL products. The major additions — ANSI/NEMA C137.9 configuration reporting and NLC-integrated thermostat information — are reported capabilities, not universal mandatory requirements. Current listings will all be able to continue, while manufacturers that support these new capabilities can update their QPL information through the application or renewal process.
DiLouie: A major change in 5.2 is a requirement that ensures energy-saving configuration settings are reported in a standardized manner. What will this look like in the QPL, and what are the benefits for NLC adoption?
Nock: Efficiency programs need confidence that controls have been properly configured to save energy. With lighting controls, installation alone is not proof of savings. Savings depend on settings such as sensor timeouts, high-end trim levels, scheduling, daylighting configuration, manual or automatic-on behavior, and how spaces are grouped. A standardized configuration report gives efficiency programs a practical way to verify that energy-saving settings were applied, without needing to interpret a different proprietary report from every manufacturer, or to decipher a collection of dozens or hundreds of screenshots from a configuration app.
Based on discussions with DLC members, it became clear that they needed a better method for substantiating the potential savings associated with NLC’s. The DLC helped to establish the ANSI/NEMA C137.9 standardized configuration report standard. NLC V5.2 recognizes NLC systems that can generate configuration reports in the standardized ANSI/NEMA C137.9 format. This is a reported capability in V5.2, not a mandatory requirement. In the QPL, users will be able to see whether or not a listed system can produce ANSI/NEMA C137.9-compliant configuration reports and filter the list for such systems.
The C137.9 standard will help efficiency programs to scale NLC incentives, by reducing administrative burden and improving confidence in claimed energy savings. It will help specifiers, contractors, and program administrators speak a common language when documenting whether a project was configured as intended. And it will help facility management staff operate and maintain each NLC system over the long term, regardless of staff turnover.
DiLouie: A second major change in 5.2 is a requirement to report capability to integrate with smart thermostats so that the lighting control system provides occupancy data as an input. What will this look like in the QPL, and again what are the benefits?
Nock: The benefit is that utilities, contractors, and customers can more confidently match an NLC system with a thermostat that has been designed to work with it. That is especially important for small and medium-sized buildings that often do not have a full building automation system. In those buildings, occupancy sensors in the lighting system can provide the real-time data needed to put HVAC zones into occupied-standby mode. By surfacing this information on the QPL, the DLC will help efficiency programs support existing incentives, design new incentives, collect better data, and encourage lighting retrofits that deliver HVAC savings in addition to lighting savings.
In V5.2, thermostat integration appears as part of the NLC system’s External Systems Integration capability. The DLC is not creating a separate thermostat QPL at this time. Instead, a thermostat is treated as an integrated feature of each NLC system from which it can easily receive occupancy data.
The QPL will show thermostat information within the system details for a listed NLC product. That information may include the thermostat manufacturer, model name and model number, whether a gateway is required, what communication protocol is used, and whether the thermostat can easily receive additional data beyond occupancy such as air quality.
DiLouie: Are there any other significant notable changes lighting practitioners need to be aware of?
Nock: LLLC systems on the DLC NLC QPL will now be directly associated with one or more LLLC luminaires or kits listed under SSL V6.0 on the DLC SSL QPL. While this change is being implemented predominately on the SSL QPL, it will help specifiers using the NLC QPL to confirm that they’ve selected a control system and luminaires or kits that are all compatible with one another.
In addition, the requirements were reorganized and clarified to improve usability, and to align better with the DLC SSL QPL of LED luminaires, lamps and retrofit kits. Capability descriptions were streamlined, and the term “Primary Use Designation” was changed to “System Scope”. Also, horticultural control systems are now allowed to qualify as NLC systems if they meet all NLC requirements, although the DLC is not separately qualifying horticultural-specific capabilities at this time.
DiLouie: The DLC appears to be focusing on NLC adoption in small and medium-sized buildings. Why are NLCs often overlooked in these applications, what is the energy savings potential, and what does the DLC hope to accomplish in terms of overcoming obstacles to adoption?
Nock: Small and medium-sized buildings are often overlooked because they are harder to serve with traditional custom efficiency programs. Large buildings are more likely to have dedicated facility staff, capital planning, and building automation systems that can support complex integration projects. Smaller buildings often lack that infrastructure. They may rely on packaged rooftop units and thermostats, have limited staff time and expertise for energy projects, and use schedules that are never fully programmed or maintained. For efficiency program administrators, these projects can be harder to reach and less cost-effective to administer one at a time.
NLCs in general, and particularly LLLC as one type of NLC, can help change that equation. Lighting retrofits are a natural point of intervention because as soon as an LLLC system is installed, networked occupancy sensors are available throughout all occupied spaces as part of the lighting system, so the occupancy data can support both lighting control and HVAC control. A lighting retrofit can save lighting energy through wattage reduction, dimming, high-end trim, scheduling, daylighting, and occupancy control. In suitable buildings, a lighting retrofit can also help thermostats reduce HVAC energy when spaces are unoccupied.
Smaller buildings are sometime beneficiaries of “Direct Install” programs, in which an efficiency program will cover the full cost of lighting retrofits in a group of small commercial buildings. Some direct install programs, such as Energy Trust of Oregon, include LLLC in many of the free lighting retrofit projects. Expanding on this opportunity, NEEA is piloting a program with Energy Trust to install 50 LLLC-integrated thermostats as part of direct install lighting retrofits.
The DLC’s goal is to make such opportunities easier to identify, specify, incentivize, and verify. By reporting which NLC systems can integrate with thermostats and which can generate standardized configuration reports, the QPL can help reduce uncertainty for contractors, utilities, and customers. The DLC is not trying to force every project into HVAC integration, but it is trying to make the best candidates easier to recognize and replicate.
DiLouie: How can lighting practitioners use the new QPL, and what should they be doing to take advantage of rebates for their customers?
Nock: Lighting practitioners should use the NLC QPL early in the project process, not after the design is already complete. The QPL can help identify DLC-qualified NLC systems, compare required and reported capabilities, verify whether a system meets utility rebate requirements, and determine whether the system supports capabilities that may unlock additional incentives.
For NLC V5.2, practitioners should pay particular attention to three areas. First, they should check whether the system can generate ANSI/NEMA C137.9 configuration reports, especially where a utility program uses reports to verify installed control settings. Second, in any space with variable occupancy, they should check External Systems Integration details to see whether the system supports integration with specific thermostats, including how that integration is configured. Third, for LLLC projects, they should coordinate the NLC system selection with compatible luminaires or kits on the SSL QPL, where relevant.
Practitioners should also contact the customer’s utility or program administrator early because incentive rules vary by market. The most successful projects will document product eligibility, control intent, sequence of operations, commissioning settings, configuration reports, and any thermostat or HVAC integration details before installation is complete.
DiLouie: If you could tell the entire electrical lighting industry one thing about NLC 5.2, what would it be?
Nock: The most important message is that networked lighting controls are becoming a platform for broader building efficiency. Occupancy data from lighting systems can help HVAC systems operate more intelligently, and standardized configuration reports can help utilities verify that control settings will save energy. Together, those changes can make advanced lighting control projects more compelling for customers, contractors, and incentive programs.
NLC V5.2 is about making lighting controls more useful as part of the whole building, not just the lighting system. The update does not simply add new paperwork or new product fields; it helps the market identify systems that can deliver deeper, more verifiable savings.
DiLouie: Is there anything else you’d like to add about this topic?
Nock: NLC V5.2 should be understood as an incremental but important step. It does not make every emerging capability mandatory, and it does not assume that every building is a good candidate for HVAC integration. Instead, it gives the market better information: which systems can support standardized configuration reporting, which systems can integrate with thermostats, and how those capabilities can be used in real projects.
That information matters because the next phase of lighting efficiency will depend on confidence, repeatability, and integration. The DLC’s role is to give efficiency programs and market actors a credible, comparable way to find products that can support those outcomes. For practitioners, the takeaway is simple: controls are no longer just an add-on to a lighting retrofit. In the right project, they are the bridge to deeper building energy savings.
To help identify and complete appropriate and successful integration projects, the DLC published in 2025 the “NLC-HVAC Integration Toolkit”, a free resource available on the DLC website. This includes a Decision Tree to help choose appropriate integration projects that are likely to save energy; and a collection of case studies with lessons learned. While most of the case studies were in large buildings with BMS or PoE, we hope to add to the collection of case studies over the next few years, as more projects are completed in smaller buildings using integrated thermostats. The case study information is currently in a large spreadsheet, but we plan to publish a more easily readable user-friendly collection of brochures summarizing each project soon.
