As many commercial building energy codes impose detailed lighting control requirements, properly documenting the control system’s intent and settings has become vitally important. Of all the possible documents describing the lighting control system, one of the most useful is the controls narrative and the sequence of operations.

While electrical contractors are often not responsible for producing the controls narrative and the sequence of operations, it is useful to understand how they work. Overall, they serve as a reference for the entire project team from design to commissioning, informing all other documentation to provide a common controls road map for the project. The controls narrative is important enough to be required by many energy codes. Versions of the ANSI/ASHRAE/IES 90.1 energy standard and the International Energy Conservation Code published over the past 10 years require that certain documentation be turned over to the owner at the project’s conclusion, including a controls narrative.

Despite this, few comprehensive resources were offering guidance about how to put these documents together. Enter the Illuminating Engineering Society, which in June 2022 published ANSI/IES LP-16-22, “Documenting Control Intent Narratives and Sequences of Operations.” At 80 pages, it discusses what to include, how to develop these documents, roles and responsibilities, and lighting controls strategies and integration.

LP-16 differentiates what it calls the control intent narrative (CIN) from the sequence of operations (SOO). The CIN expresses intent and is therefore general, written in plain language and easily understood by the owner. It provides a foundation for the SOO, which includes detailed control behavior and resulting settings that can be used to calibrate and program the system.

From CIN to SOO and beyond

The CIN starts with a general description of the project goals, which in turn reflect the owner project requirements. It then describes control strategies that will be deployed to satisfy the goals. A description of the control system will be needed to execute the strategies, which might state conceptual preferences regarding topology, integration, user interfaces, emergency lighting and more. A basic sequence of operations for each space type is then added to complete a springboard for the SOO.

LP-16 outlines a series of steps to produce a CIN. The design team reviews the owner project requirements, energy codes and other requirements to outline exactly what it must provide. After this, the project and its characteristics are evaluated, noting space types and their function, schedules and characteristics such as daylight availability. 

Armed with this information, the design team determines how each space type should be addressed by the control solution, noting any interactions between devices and points of integration with other systems. The control purpose and appropriate strategies are defined. Building on this, the team then identifies desired control inputs, outputs and behaviors that will form the basis for desired settings, noting the scale of system—such as one that implements some control strategies globally across a building or multiple space types while executing others locally.

At the end of all this, the design team reviews its work to ensure the concept is comprehensive and satisfies the owner project requirements (or otherwise justifies deviations). Note the CIN ideally should be treated as a living document, building and clarifying information until it is completed over the course of the project.

The SOO carries the CIN forward to an actionable, technical document that may be enforceable. It describes how each of the CIN’s control solutions in each space type will specifically be accomplished. Again, LP-16 identifies appropriate steps for developing this tool.

All space types are listed, and the design team ensures all strategies, control zoning and sequences of operations required by energy codes are incorporated while confirming the system addresses the owner project requirements. The design team then defines system behavior in each space, describing what and how specific actions occur, along with settings. Finally, the design team reviews the SOO to ensure it addresses all functional and integration requirements.

While the above may be expressed in a basic text table showing 1) space type, 2) CIN and 3) SOO, an additional powerful tool is the SOO matrix, which lists space types vertically and control strategies, equipment and special components such as emergency lighting control horizontally, with checks in the resulting matrix showing in which spaces the control types will be applied. As with the CIN, the SOO matrix should build as a living document, eventually adding detail such as design light levels, notes providing details, room numbers and references to sequences of operations.

Executed with discipline, a CIN and SOO provide clear expectations for delivering a lighting control system that satisfies the owner’s requirements. As such, taken as guide or inspiration, LP-16 is worthy of every lighting control system designer’s toolbox.

Check it out at the IES bookstore at https://bit.ly/3uDpsQZ.