What Is a Lighting Plan?

A tag such as A1 or F2 next to each luminaire points to the luminaire schedule, which lists the basis of design, source, lumens, color temperature, voltage, mounting, and driver. A fixture with no matching schedule row cannot be priced, and a schedule row with no fixtures on any plan usually means a type was deleted from the design and left behind on the schedule.

Dimming protocol belongs on the schedule too. A 0-10 volt driver, a DALI driver, and a forward-phase driver need different control wiring, so the lighting plan, the schedule, and the control narrative have to agree on which one each type uses.

Energy codes now dictate much of what a lighting plan shows: local control in each space, occupancy or vacancy sensors in offices, classrooms, and restrooms, automatic shutoff, and daylight-responsive controls in the daylight zones beside windows and under skylights. ASHRAE 90.1 Section 9.4.1 and IECC Section C405.2 list which space types need which functions.

On the plan, controls appear as sensor symbols, switch legs, daylight zone boundaries, and sometimes a lighting control panel or relay cabinet. A sequence of operation ties them together, and plan reviewers read the narrative against the symbols.

The energy code caps installed lighting watts per square foot, either for the building as a whole or space by space. Fixture counts on the plan multiplied by the schedule wattages have to come in under that allowance, which is why the compliance report, often from the DOE COMcheck tool, is checked against the plan.

A value engineering swap to a cheaper fixture with a higher wattage can push a space over its allowance without anyone touching the plan, because the schedule change alone does it. Rerun the compliance report whenever a fixture type changes.

NFPA 101 Section 7.9 requires emergency lighting along the means of egress to provide an initial average of 1 foot-candle and a minimum of 0.1 foot-candle at the floor, for 90 minutes after normal power fails. The lighting plan shows which fixtures are on emergency circuits, battery packs, or a central inverter, and where exit signs go.

Fixtures fed from a generator or a central inverter belong to an emergency system under NEC Article 700, which has its own wiring separation and transfer equipment requirements. A fixture tagged as emergency but circuited to a normal panel is one of the easiest errors to miss on a crowded plan.

The architect often draws fixture locations on the RCP as ceiling design intent, then the electrical drafter brings them onto the lighting plan by xref or by tracing. When the RCP changes, a traced lighting plan drifts, leaving fixtures in a grid that moved or on top of a diffuser that was relocated.

Referencing the current architectural RCP as the background and keeping fixture blocks on electrical layers, such as the E-LITE group in the US National CAD Standard, makes a reload show the conflict instead of hiding it.