Wall Pack Lighting Layout & Photometric Guide

Core Concepts: Illuminance & Uniformity

Illuminance (foot-candles or lux) is the light that reaches the ground or task plane. For exterior pathways and building perimeters, your goal is consistent light without harsh bright spots or dark pockets. A well-planned wall pack lighting layout should feel calm to the eye and supportive of wayfinding and security.

• Average vs. minimum: Don’t chase a big average at the expense of a low minimum; people notice the dark spots first.
• Uniformity ratio (Avg:Min): Lower ratios mean smoother light. Aim for practical uniformity—get it acceptable, then stop. Over-lighting creates glare and cost.
• Context: Security, cameras, and neighboring residences may require different targets and distributions. There is no single number that fits every façade.

Reading Photometrics (IES Files & Charts)

Manufacturers provide IES files and charts that plot light levels across an area. You don’t need to be a lighting designer to get value from them—scan for these cues:

• Iso-foot-candle plot: Contours show how far useful light travels and where edges fall. Use the legend to spot rapid falloff near property lines.
• Distribution type: Tells you the lateral spread—crucial for predicting throw along the wall or across a yard.
• Mounting height assumed: If the chart assumes 15 ft and you’ll mount at 20 ft, expect wider spacing but lower intensity per square foot.
• Output mode: If the luminaire is field‑selectable (e.g., 40/60/80W), confirm which setting the photometric file reflects.

Tip: Build a small library of IES files for your preferred families (Type II/III/IV options, multiple lumen packages). Side‑by‑side plots speed up value engineering and help justify choices to your AHJ or owner.

Picking the Right Distribution (Type II/III/IV)

“Best” distribution depends on the task, property line, and mounting height. Here’s the quick read for photometric wall pack spacing decisions:

• Full-cutoff wall packs: Keep uplight to near‑zero. Ideal near residences/campuses and for dark‑sky‑sensitive zones.
• Type II / Type III: Common for walkways and building faces. Type II is narrow/elongated; Type III reaches a bit wider—often a sweet spot for façades.
• Type IV (forward throw): Pushes light outward to cover loading docks, aprons, or lot edges. Great for “yard‑side” reach from the building.
• Adjustable/tilting heads: Helpful when site elements vary. Use tilt sparingly to avoid glare and uplight.

Match distribution to the task: close‑in walkway coverage vs. forward reach for large aprons. If in doubt, plot two candidates (e.g., Type III and Type IV) at your mounting height and compare uniformity at the property line.

Mounting Height & Spacing (Rules of Thumb)

Exact spacing depends on distribution, lumen output, and mounting height, but these ballparks help rough in a layout before formal calcs:

• 10–12 ft mounting height: spacing ≈ 1.0–1.25× height (10–15 ft).
• 15–20 ft mounting height: spacing ≈ 1.25–1.75× height (19–35 ft).
• Forward‑throw on wide areas: you can stretch spacing—but watch uniformity and glare at windows and cameras.

Need lumen selection and equivalencies? Use the companion HID→LED sizing & spacing guide for starting lumen classes, then tune with photometrics.

Spacing‑to‑Height Ratio (SHR) & Quick Calculator

SHR is a handy shortcut when you don’t have software handy. It’s simply the center‑to‑center spacing divided by mounting height. Many good wall pack layouts land between 1.0 and 1.6 depending on optic and lumen package.

1. Pick a tentative SHR (e.g., 1.3 for a Type III at 15 ft).
2. Multiply by mounting height (1.3 × 15 = ~20 ft spacing).
3. Check the IES plot at your height. If edges look thin (low minimums), reduce spacing to ~18 ft. If you’re over‑bright, either dim or step down a lumen package.

Note: SHR is not a code metric; it’s a design convenience to get you close before you verify with a plot or a night walk.

Site Types & Quick Layout Recipes

Doorways & exit discharge

Goal: clear recognition of the door, safe step‑off, and adequate light for cameras. Use a full‑cutoff optic to avoid glare at eye level. Typical picks: 2,000–3,000 lm at 10–12 ft mounting, SHR near 1.0–1.2, and level aiming. If a wall pack supports the egress path at night, verify emergency strategy elsewhere (this article focuses on layout; see your life‑safety plan for specifics).

Perimeter walkways

Goal: smooth, continuous light along the path without hot spots. Type II or III at 12–16 ft works well. Start around SHR 1.2–1.5, then tighten near corners/changes in grade. Warmer CCT (3000–4000 K) near residences reduces perceived glare.

Loading docks & wide aprons

Goal: broader “yard‑side” coverage and camera clarity. Type IV (forward throw) at 16–20 ft with a mid/high lumen package. Begin around SHR 1.4–1.6 and tune based on photometric edges. Consider shields if the view from the yard side is sensitive.

Campus edges & neighbor‑sensitive facades

Goal: minimize trespass and skyglow. Choose dark‑sky friendly wall packs (full‑cutoff + shields) and lower CCT (~3000–3500 K). Keep aiming level and rely on the right optic rather than tilt. For a deeper dive, see Dark Sky Friendly Wall Packs: Full‑Cutoff & Shielding.

Fast Layout Workflow (7 Steps)

1. Define the task: perimeter patrol, doorway safety, dock visibility, or camera support.
2. Select distribution & CCT: full‑cutoff near neighbors; Type III for façades; Type IV for yard‑side throw. 3000–4000 K when neighbor‑sensitive; 4000–5000 K for security/camera contrast.
3. Choose mounting height: balance reach vs. glare; confirm structure supports the weight and exposure.
4. Rough spacing via SHR: pick 1.2–1.5 as a start (depending on optic), then multiply by height.
5. Validate with photometrics: review the IES at your height; check uniformity, edges, and property lines.
6. Plan controls: photocell for dusk‑to‑dawn; add motion/bi‑level if policy or energy code requires it. California projects often trigger occupancy + reduction—see Title 24 outdoor lighting basics.
7. Document: save plots, model/SKU, and control set‑points in the maintenance log for future service.

Aiming, Glare Control & Dark‑Sky Tips

• Aim level first: start with zero tilt on cutoff optics; add tilt only if you need more throw. Tilting increases brightness at the source and can create uplight.
• Shield when needed: visors/house‑side shields block direct view from windows and cameras, especially at higher wattages.
• Reduce spill: lower output, pick a tighter optic, or step down mounting height. Near residences, consider 3000–4000 K to soften perception.
• Controls & dimming: dusk‑to‑dawn plus vacancy reduction keeps nights calm and saves energy. Tune bi‑level set‑points so cameras still perform.

Cameras & Security Considerations

Lighting and cameras should be planned together. High contrast can help analytics, but extreme glare blinds lenses. A few tips:

• Keep sources out of frame: avoid pointing wall packs into the camera FOV; use shields if you must aim near the lens.
• Favor uniformity on walk paths: smoother light helps motion detection and reduces false triggers.
• Coordinate dim levels: set vacancy scenes (e.g., 50–70%) high enough for camera clarity but low enough to curb complaints.

Night Verification & Adjustments

1. Walk the site: check for dark pockets, scallops on the wall, glare at doors, and camera visibility.
2. Tweak aiming: small tilt changes can fix hot spots without creating uplight. Re‑walk after each change.
3. Finalize controls: set time delays and bi‑level thresholds; label circuits/groups for future service and acceptance testing.
4. Document: save layouts, IES references, and settings in the maintenance log. Good documentation speeds approvals and future troubleshooting.

Resources

• How to Size Wall Pack Lights — HID→LED Replacement Chart (blog)
• Dark Sky Friendly Wall Packs: Full‑Cutoff & Shielding (blog)
• Title 24 Outdoor Lighting — Controls & Compliance (page)

FAQ

How far apart should wall pack lights be?

A practical starting point is spacing around 1.2–1.5× the mounting height, then adjust based on photometrics. For example, at 15 ft, begin ~18–22 ft apart and tune for uniformity.

What is the best mounting height for wall packs?

Pick the lowest height that achieves the reach your task needs. 10–12 ft is common for doors and short walks; 16–20 ft for loading areas or broader coverage—always verify with an IES plot.

Do I need a full photometric study?

For complex or security‑critical sites, yes. For straightforward retrofits, rules of thumb plus a quick IES review often suffice, followed by a nighttime walk to confirm.

How do I limit complaints from neighbors?

Use full‑cutoff optics, keep aiming level, consider 3000–4000 K CCT, add shields, and dim during off‑hours. If trespass is still high, step down the lumen package or tighten spacing.