Primary audience: Specifying engineers
Define the outdoor review before choosing a rating
A specifying engineer needs to know which surfaces require light and which neighboring areas need protection from spill. Begin with the site boundary, roads, walkways, occupied windows and the applicable outdoor-lighting requirements. A product label cannot describe all those relationships.
BUG stands for backlight, uplight and glare. The three letters describe separate aspects of a luminaire's distribution. Read each component of the rating rather than collapsing the result into a single “good” or “bad” score. The site's permitted values depend on the applicable review framework and conditions. Each component uses a scale from 0 to 5; lower values indicate tighter control in that category. See the IES BUG rating tables.
The DarkSky and IES Model Lighting Ordinance provides a published example of using BUG information with lighting zones and site conditions. It is a model document, not evidence that your jurisdiction adopted its requirements. Check the actual ordinance and project specification.
Write the applicable criteria on the lighting plan before comparing fixtures. This gives reviewers a shared basis for assessing the proposed optics, mounting and operating schedule.
Separate distribution, cutoff language and programme approval
Distribution descriptions, BUG ratings and DarkSky programme approval are related to outdoor lighting, but they are different evidence. One field cannot substitute for all the others. Request the document that answers the requirement actually written in the project specification.
| Information | Useful for | Does not establish |
|---|---|---|
| Distribution type | Understanding the shape of delivered light | A specific BUG rating or boundary result |
| BUG rating | Reviewing backlight, uplight and glare components | Installed-site acceptance on its own |
| Cutoff description | Understanding a stated optical characteristic | Every current project requirement |
| DarkSky programme record | Checking approval under that programme | Automatic compliance with a local ordinance |
| Project calculation | Evaluating the selected installation geometry | Unmodeled field changes |
The DarkSky glossary describes legacy full cutoff as zero intensity at or above horizontal, plus limits at high angles below horizontal. The older cutoff system has been replaced by the luminaire classification and BUG system. A U0 entry alone is not a complete full-cutoff assessment.
Do not translate “Type II” or a downward-looking housing into “full cutoff.” Likewise, a low uplight component does not answer every glare question. Keep the original terminology and review the photometric evidence for the exact configuration.
If a specification uses an ambiguous phrase such as “dark-sky compliant,” ask the designer to identify the intended criteria and evidence. Resolve the meaning before the purchase order fixes a model.
Check the model row and the installed aiming
The AR07 area-light page publishes model-specific BUG entries: AR07-150W-H-TCP has B3 U3 G3; AR07-200W-H-TCP has B4 U4 G4. AR07-300W-H-TCP has B3 U3 G3; AR07-500W-H-TCP has B4 U4 G5. These are the published rows, not a universal family rating.
Do not average those entries or borrow one from a lower-output model. For field-selectable equipment, request confirmation that the data used for review represents the selected output and optic. A setting change belongs in the design record when it affects the basis of the calculation.
The WK06 wall-pack page publishes Type II distribution. That description does not authorize a full-cutoff or DarkSky approval claim in this guide. Match its actual documentation to the project requirement.
Also record mounting height, tilt, rotation and shielding. The direction a luminaire faces matters to the installed result. A calculation using a level fixture cannot support an unexplained upward tilt in the field. Review revised aiming before accepting the installation.
Apply the five outdoor-lighting principles to the schedule
DarkSky and IES's five principles call for lighting that serves a purpose, reaches the intended area, uses appropriate levels, operates when needed and considers warmer color. Use those principles as design questions, not as a new product certification.
For each fixture group, write the task it serves. An entrance, loading area and perimeter walk may have different hours and visual needs. This helps the designer avoid treating every exterior circuit as if it must operate identically all night.
Add the controls sequence to the schedule. Identify any dimmed state, occupancy response, time schedule and manual override needed by the project. Then check that the selected equipment and accessories actually support the sequence. A photocell can respond to daylight without establishing all-night dimming behavior.
Review operating modes in the calculation where they affect required performance. An after-hours setting must still serve the task specified for that period. Record the approved settings at commissioning so staff can distinguish an intentional low-output condition from a fault.
Prepare the outdoor submittal checklist
Give the reviewer enough information to reproduce the design assumptions. A product sheet and a colored site image are incomplete without the selected configuration, calculation criteria and geometry.
- Site plan with boundaries, adjacent uses, pedestrian routes, roads, mounting positions and relevant obstructions.
- Applicable local requirements and project criteria, with the responsible designer's interpretation of ambiguous terms.
- Exact model, optic, selected output, CCT, mounting accessories and any shielding used in the calculation.
- Configuration-matched photometric file and available BUG documentation, with source dates and revisions.
- Calculation results, mounting heights, aiming, controls sequence and the commissioning settings record.
Make departures easy to find. If a proposed alternate needs a different mount or optic, show that change beside the original requirement. Do not bury it in a revised file name.
At handover, compare installed aiming and settings with the approved plan. Retain the final record for later service. A replacement should preserve the reviewed arrangement or trigger a deliberate design review.
Related guides
- LED Wall Pack Buying Guide: Optics, Controls and Voltage
- Parking Lot LED Lighting: Choosing Shoebox Area Lights
- Lighting Spec Sheets and IES Files: Submittal Guide
Request configuration-matched design documents.
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