Adding an equipment platform means the existing layout can't be assumed to still work. You need to check two surfaces separately: the surface where people work or walk on the platform, and the area below it, where the deck and framing may block some light. Keep the current layout only after both levels have been reviewed.
How much the platform changes conditions below depends on its geometry and on where the fixtures sit relative to it. Treat that effect as something to check, not as a known result. Once both levels are reviewed, the team can decide whether to keep the layout, request a project-specific photometric review, or discuss a revision.
Review both levels before retaining the lighting layout
A floor-level lighting plan answers a floor-level question. It doesn't show what happens on a raised deck, and it may not show what happens under one. DOE measurement guidance offers a useful general framework here, advising teams to identify the appropriate task plane and note any point shaded by fixed obstructions.
That guidance comes from a general lighting measurement protocol, not a platform-specific rule. It still maps onto the two jobs an equipment platform lighting review has to do. First, define the activity and surface on the platform. Second, look for fixed platform parts that may shade relevant points below. Until both are done, treat the existing layout as the starting point for review, not proof that it still works.
Identify the platform-level task surface
What happens on the platform sets the surface you assess. Because the deck's height alone doesn't define the task, DOE guidance suggests selecting task planes based on specific activities. Record the platform's use in plain terms, then pick the surface to match:
- Regular work area: If people will operate, inspect, or service equipment at a bench, panel, or console on the platform, assess that work surface at its actual height.
- Access or service walkway: If the platform mainly serves foot traffic to reach equipment, assess the walking surface at the deck's elevation.
- Mixed use: If one part is a work station and another is a walkway, record both surfaces and where each one sits on the deck.
Write down the deck elevation and any work-surface heights. The reviewer will need them later. The platform doesn't automatically call for a different fixture type or a higher fixture count. The surface definition just tells the reviewer what to evaluate. If the new deck is effectively a separate use area, it can help to treat it as one of several commercial lighting zones with its own task description.
Check the area below for possible obstruction
The space under and around the platform needs its own check. The deck, framing, and underside mounts can sit between a light source and a lower task surface. According to CIE guidance on obstructed interiors, objects between sources and tasks block direct light and may reduce planar illuminance, with the exact impact depending on geometry.
That CIE publication describes calculation methods accounting for contents above and below the working plane. Use these points to structure the lower-level check:
- Platform geometry: Note the footprint, deck elevation, deck construction (solid or open), and underside elements such as beams, ducts, or cable trays.
- Fixture relationship: Mark which existing luminaires sit above, beside, or near the platform edge, so the reviewer can see where the deck may cut into their light.
- Lower-level surfaces: Identify the actual work surfaces or walking routes below and next to the platform, not just open floor.
- Points to note: If the team takes measurements, follow DOE guidance to note measurement points partly shaded by fixed obstructions. The same protocol suggests sampling interior points both below and between fixtures.
Overhead equipment in other settings raises a similar question. Our guide to crane shadows in fabrication bays covers a related layout challenge.
Assemble the platform and lighting-plan information
A reviewer can only assess what the drawings and notes actually show. For general lighting simulation, DOE FEMP simulation inputs include space dimensions, work-surface heights, and luminaire positioning. The platform details below add the practical project information required to model the new structure accurately.
Platform and activity details
- Platform footprint and location in the space
- Deck elevation and any work-surface heights on the platform
- Deck construction and underside elements that may block light
- Intended activity on the platform and in the area below
Existing space and lighting details
- Space dimensions, including floor-to-ceiling height and lower-level work-surface heights
- Current fixture layout drawing
- Luminaire position, orientation, angle, mounting type, and mounting height
- Photometric files and calculation inputs from the existing plan, if available
Square footage alone won't answer this. Our article on lighting plan inputs explains why the space and fixture details matter more than a simple fixture count.
Choose whether to retain, model, or revise the layout
The decision depends on whether the review actually covered both levels and the platform's geometry. Use the table to match what the review found with the next step.
| Review finding | Decision | Next step |
|---|---|---|
| Both surfaces and platform geometry represented | Keep layout under review | Compare results with project criteria |
| Platform surface or geometry missing from the plan | Request project-specific photometric review | Send the platform and fixture data |
| Review shows a surface not addressed under project criteria | Discuss a layout revision | Work options through with the project designer |
A project-specific simulation is often how the second row gets resolved. Read its results as estimates. DOE FEMP's caveat that simulation is approximate and assumption-dependent notes that actual illuminance values may vary based on the assumptions used in the model. Ask how the platform deck and underside were represented before relying on the output.
Whether a result warrants revision depends on the project's own lighting criteria and the designer's judgment. If code or permit requirements apply, confirm them with the authority having jurisdiction, because adopted rules vary by location. When the existing plan can't represent both levels, our lighting design support is one place to start a project-specific review.
FAQs
Does an access-only platform still need its own lighting check?
Yes. Even if no one works at a bench up there, people still walk the deck. The walking surface at deck elevation is the surface to define and assess. For walking-focused activity, DOE's task-plane guidance for activity-specific surfaces points to floor level, which here means the platform floor.
Does adding a platform mean we need more fixtures?
Not automatically. The platform creates new conditions to evaluate, but the guidance behind this review covers how to assess surfaces, not how many fixtures to add. A fixture change makes sense only if a project review finds a surface the current layout doesn't adequately address under the project's criteria.
Will a lighting simulation show exactly what the finished space looks like?
No. A simulation is an estimate built on the dimensions, fixture data, and assumptions entered into the model. Built conditions can differ, especially if the platform's deck or underside was simplified in the model. Treat the result as decision support, and confirm critical surfaces after installation when that matters to the project.
Should we measure light levels after the platform is installed?
Field measurements can confirm conditions the model only estimated. Take readings at the actual task surfaces on both levels, sample points both below and between fixtures, and note any point the platform shades, even partly. Those notes show the reviewer where the deck affects results instead of leaving it to assumption.
