NCQLP Study Guide 2026: The 12 Topics You Must Master

This foundational domain covers the physics of light — electromagnetic spectrum, wavelength and color perception, the human visual system (photopic vs. scotopic vision), colorimetry, and color temperature. Expect questions on Kelvin values, the chromaticity diagram, metameric pairs, and how the eye adapts to different luminance levels. Candidates who are weak here struggle across multiple other domains because so much later content builds on these fundamentals.

LED technology dominates this section. Topics include semiconductor physics at a conceptual level, lumen depreciation (L70/L80/L90 ratings), driver types (constant current vs. constant voltage), thermal management, phosphor conversion vs. direct-emit LED, and comparisons to legacy sources (fluorescent, HID, halogen). Questions often present a scenario and ask which light source characteristic makes it appropriate or inappropriate for the application.

Photometry is where many candidates lose the most points — and where consistent study pays off most. Know the relationships between candela, lumen, footcandle, and lux. Master the inverse square law (E = I/d²) and the cosine correction for non-perpendicular surfaces. Understand IES LM-63 file format, polar and isofootcandle diagrams, and how photometric reports are used in lighting software. The exam will test calculations, so practice them.

Controls content spans occupancy and vacancy sensors (PIR, ultrasonic, dual-technology), daylight harvesting strategies (open-loop vs. closed-loop), DALI protocol (IEC 62386 — 64 addresses per bus, 16 groups), 0-10V dimming, wireless systems (Bluetooth mesh, Zigbee), and tunable white concepts. Energy codes increasingly mandate controls, so this domain intersects heavily with the ASHRAE 90.1 section. Know commissioning requirements.

ASHRAE 90.1 regulates commercial buildings via LPD (watts per square foot) limits using the Space-by-Space Method or Building Area Method. Title 24 applies to California projects and has its own LPD tables and controls mandates. The IECC addresses residential and light commercial. The exam typically presents a space type and asks which LPD limit applies or whether a proposed design complies. Know the difference between mandatory measures and prescriptive paths.

IES distribution type classifications (Type I through V, full-cutoff, semi-cutoff) and their appropriate applications are heavily tested here. Light trespass, skyglow, and obtrusive light are defined and regulated by IDA/IES Model Lighting Ordinance and LEED SS credits. Parking lot design, roadway uniformity ratios (average-to-minimum, max-to-min), and luminaire mounting height relationships are all exam-testable. Know BUG (Backlight, Uplight, Glare) ratings.

NFPA 101 (Life Safety Code) governs emergency lighting in commercial occupancies. The critical values: 1 footcandle minimum at floor level along egress paths, 90-minute minimum battery duration, 0.1 fc at end of emergency period. Egress illumination requirements differ from exit sign illumination requirements — know both. Also know the difference between centrally powered emergency systems and unit equipment (self-contained batteries), and when each is appropriate.

Daylighting content includes window-to-wall ratio, sidelighting vs. toplighting strategies, light shelves, shading coefficients, and the relationship between daylight factor and climate. Daylight harvesting controls (photosensors, blinds integration, dimming curves) and their commissioning requirements are tested alongside LEED Daylight credit metrics, including spatial daylight autonomy (sDA) and annual sunlight exposure (ASE). Know the difference between sDA and daylight factor.

This is an emerging but increasingly tested domain. Melanopsin-driven circadian responses are driven by the intrinsically photosensitive retinal ganglion cells (ipRGCs), which are most sensitive to short-wavelength (~480nm) light. Metrics include melanopic equivalent daylight illuminance (EDI) from WELL, and circadian stimulus (CS) from LRC research. The WELL Building Standard's Light concept is the primary framework tested — know its preconditions and optimizations.

This domain covers the full design workflow: programming (understanding owner requirements), schematic design, design development, construction documents, specifications (prescriptive vs. performance), photometric calculations, submittal review, and commissioning. Understand when lighting schedules, cut sheets, photometric plans, and reflected ceiling plans are used. Questions often involve identifying the appropriate deliverable for a given project phase or interpreting specification language.

Life-cycle cost analysis, simple payback calculations, return on investment, and demand charge reduction are all tested. The exam expects you to recognize which factors drive a retrofit's economics — not to perform complex financial modeling. Know the difference between installed cost, operating cost, and maintenance cost (lamp and ballast replacements). Understand how utilities structure incentives and rebates, and how to calculate annual energy cost (kWh × rate).

LEED v4.1 EQ credits for Interior Lighting, Daylight, and Quality Views; the WELL Building Standard's Light concept; and ENERGY STAR qualification criteria for luminaires are the primary frameworks. Also know Dark Sky (IDA) principles, the relationship between LPD compliance and LEED EA credits, and how sustainable design intersects with the visual comfort and biological performance goals of WELL. These are increasingly integrated rather than siloed topics.

All 12 modules. 74 lessons. 129 timed practice questions.

LC · Lighting Master sequences every topic in the order that builds the most durable comprehension. 24 CEU credit hours included.