Planning a new warehouse, factory, or retrofit shop and wondering how many UFO high bay lights you really need—and where to put them? A proper photometric layout answers that question with data instead of guesswork, and getting one free is often the lowest‑risk way to de‑risk a six‑figure project.
In this article, you will see exactly what a free UFO high bay photometric layout includes, what information you need to provide, and how professionals use IES files, LM‑79 data, and lighting software to size and place fixtures correctly. The goal is simple: help you submit a complete layout request so the first design you receive is close to “permit‑ready” and rebate‑ready.
What You Actually Get with a Free UFO High Bay Photometric Layout
A serious layout service is more than a colorful isolux picture. When done properly, it combines:
- Accurate luminaire data (IES files from LM‑79 testing)
- Realistic maintenance factors (dirt, lumen depreciation, and temperature effects)
- Code‑aligned target illuminance for your application
- Controls and rebate assumptions that match DLC and utility requirements
According to the Illuminating Engineering Society (IES), photometric calculations should be based on LM‑79 tested performance to define total lumens, efficacy, and distribution, not marketing claims. Their LM‑79-19 standard describes how to measure luminous flux, input power, and color under controlled conditions. A credible free layout uses these LM‑79‑derived IES files as the engine.
Typical deliverables you should expect
A professional UFO high bay layout package usually contains:
- Plan view with fixture locations and aiming (if tilt is used)
- False color / isolux plots showing illuminance (lx or footcandles) on the workplane
- Numerical calculation grids in key areas (aisles, packing, assembly zones)
- Summary metrics: average/minimum illuminance and uniformity (avg:min)
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Assumptions sheet listing:
- Room and mounting heights
- Surface reflectances (ceiling/wall/floor)
- Light loss factor (LLF) and components
- Operating hours and basic controls strategy
This assumptions sheet is what utility reviewers and many Authorities Having Jurisdiction (AHJs) care about most. As highlighted by the DIALux lighting design guidance, using realistic LLFs and correct room parameters can change maintained illuminance predictions by 10–30%, which is the difference between passing and failing a standard such as EN 12464‑1.
Why a Photometric Layout Beats “Rule of Thumb” Sizing
Many buyers start with watt‑for‑watt replacement tables or online calculators. Those have their place, but they ignore factors that dominate perceived brightness and compliance in real spaces.
The limits of simple watt replacement
Conventional wisdom says you can choose UFO high bays simply by replacing a 400 W metal halide with a 150–200 W LED. In practice, spacing, mounting height, room reflectances, and vertical illuminance often have more impact than raw watts. Industry texts such as Interior Lighting for Designers show that a change from a 20 ft to a 30 ft mounting height can drop task lighting levels by 30% or more if spacing and optics are not adjusted.
There is also a common misconception that catalog lumens equal delivered lumens in your building. That is rarely true. Our analysis aligns with the DIALux documentation: when you derate for driver losses, ambient temperature, dirt, and lumen depreciation, maintained light levels can be 10–30% lower than initial values.
Why IES files and LM‑79 data matter
Each UFO high bay model has a unique photometric fingerprint. The IES LM‑63 format defines how this data is stored in .ies files so that tools like DIALux or AGi32 can simulate light distribution consistently. The IES approved method for this format is described in their LM‑63-19 standard.
For your free photometric layout, those IES files allow the designer to:
- Predict average and minimum illuminance on workplanes
- Check uniformity ratios in aisles and open areas
- Evaluate glare and high‑angle light for comfort and safety
A layout that does not use proper LM‑79‑derived IES data is essentially a guess dressed up as a heatmap.
Real‑world case snapshot
- A 30,000 ft² bulk storage warehouse at 28 ft mounting height
- Initial “rule of thumb” design: 60 UFO high bays at 150 W each
- Photometric layout using LM‑79 IES data and realistic LLF = 0.75
Results:
- Rule of thumb: predicted 30 fc average (no LLF or reflectance considered)
- Actual layout: 22 fc maintained average, average/minimum uniformity ≈ 0.35
To meet typical storage recommendations (around 20–30 fc with 0.4–0.6 uniformity), the designer adjusted spacing and added 6 fixtures. The free layout prevented a costly under‑lighting mistake that would have been discovered only after installation.
Information You Need to Submit for a High‑Quality Free Layout
The quality of your UFO high bay layout is directly tied to the quality of the information you provide. A floorplan alone is often not enough.
Essential project inputs checklist
Use this checklist when you request a free photometric layout:
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Drawings
- PDF floorplan and, if available, CAD files (DWG/DXF)
- Indicate racking, machinery, or mezzanines
- Mark areas with different tasks (storage, packing, assembly, loading docks)
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Heights
- Finished floor to ceiling/roof height
- Planned mounting height of UFO high bays (bottom of fixture)
- Any suspended elements that reduce effective height
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Surface reflectances
- Typical defaults: ceiling 70%, walls 50%, floor 20%
- Tell the designer if you have dark walls, open steel deck, or very dirty environments, as this can drop reflectances to 30/30/10 or lower.
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Lighting requirements
- Target light levels if known (lux or footcandles)
- Tasks performed in each area (bulk storage vs. detailed assembly)
- Any standards you must align with (e.g., internal safety policies, client specs)
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Controls and operating hours
- Estimated hours per day and days per week
- Planned occupancy/daylight sensors or schedules
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Existing conditions (for retrofits)
- Existing fixture types, wattages, and counts
- Pictures of typical areas
The AGi32 documentation and related CAD integration guides emphasize this same data set—mounting heights, reflectances, and obstructions—as critical inputs. They demonstrate that inaccurate heights or missing obstacles can change predicted illuminance by 20% or more in industrial spaces.
Recommended target illuminance and uniformity ranges
For many warehouse and industrial projects, designers reference recommendations from IES documents such as ANSI/IES RP‑7 (lighting for industrial facilities). While every project is different, a practical design heuristic for maintained illuminance is:
| Area type | Maintained illuminance (typical range) | Notes |
|---|---|---|
| Bulk storage / general warehousing | 30–75 lux (3–7.5 fc) | Emphasis on safety and navigation |
| Packing / shipping | 200–300 lux (20–30 fc) | Reading labels, avoiding errors |
| Detailed assembly / inspection | 300–500 lux (30–50 fc) | Fine visual tasks |
Designers also aim for average:minimum uniformity ratios of about 0.4–0.6 in active work areas. Poor uniformity (e.g., 0.2) often leads to complaints even when average illuminance technically meets a spec.
For a deeper dive on how illuminance and uniformity affect operations, see the separate guide on Designing a High Bay Layout for Warehouse Safety.
How Professionals Build a UFO High Bay Photometric Layout
A credible free layout follows the same technical steps lighting designers use on paid projects.
Step 1: Select candidate fixtures and optics
The designer starts from your ceiling height, room size, and application to choose:
- Nominal lumen package (e.g., 15,000–30,000 lm)
- Beam distribution (wide vs. medium vs. narrow)
- Color temperature and CRI appropriate for the work (e.g., 4000 K for visual comfort, 5000 K for higher contrast)
For guidance on lumen levels at different mounting heights, the article Warehouse Lumens Guide for UFO High Bay Lights explains how lumen output, mounting height, and spacing interact in typical warehouses.
Step 2: Import IES files and define the environment
Using software such as DIALux or AGi32, the designer then:
- Imports the IES (.ies) files that encode the luminaire’s distribution per IES LM‑63-19
- Draws or imports the floorplan and sets room heights
- Assigns surface reflectances, either per your data or reasonable defaults
Here a common failure appears. According to experienced practitioners and tools documentation like DIALux’s LLF examples, designers often:
- Leave ceilings and walls at unrealistically high reflectances
- Ignore shelves or machinery that block light
The result is layouts that overstate actual illuminance by 10–30% once the building is occupied.
Step 3: Apply Light Loss Factors (LLF)
The Light Loss Factor combines all the ways a system loses light over time:
- Lumen depreciation of the LEDs (from LM‑80 data and TM‑21 lifetime projections)
- Dirt accumulation on fixtures and room surfaces
- Temperature and driver losses
The IES Lighting Handbook shows that in many industrial conditions, maintained illuminance after several years can be 20–40% lower than initial levels if dirt and depreciation are ignored. A practical heuristic is to work with LLFs between 0.7 and 0.85 depending on cleanliness and maintenance intervals.
Your free layout should explicitly state the LLF used and why. If not, ask for it.
Step 4: Run calculations and optimize spacing
Designers then iterate on:
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Fixture spacing using spacing‑to‑mounting‑height (S/MH) ratios
- 1.0–1.5 for aisles and task areas
- Up to 1.5–2.0 for general storage
- Row locations aligned with racking or process lines
- Controls zoning so that occupancy sensors and dimming match usage
Research insights from professional practice (summarized in the Interior Lighting for Designers reference and field data) show that tightening S/MH from 1.8 to 1.2 in key tasks can increase minimum illuminance by 25–35%, dramatically improving uniformity without changing fixture type.
For projects that plan dimming and zoning, the article How to Zone UFO High Bay Dimming Controls offers practical zoning patterns for warehouses and production areas.
Step 5: Integrate controls and rebate assumptions
Expert Warning
A common belief is that controls can be added after finalizing the layout. Real‑world rebate reviews and operating data show the opposite. As the DesignLights Consortium guidance on networked lighting controls makes clear, utilities evaluate both the luminaire efficacy and the controls strategy (scheduling, daylighting, and occupancy sensors) when determining incentive levels.
If the free layout assumes 16 hours/day of full output but the actual system will dim to 20–40% in unoccupied aisles, your energy and rebate calculations will be wrong. Good layout requests therefore specify:
- Expected hours at full output vs. dimmed levels
- Areas that will use occupancy sensors, vacancy sensors, or time scheduling
- Any daylight zones near skylights or clerestory windows
When this information is modeled up front, the photometric layout can support both safety compliance and rebate documentation instead of being a purely visual artifact.
Pro Tip: Don’t Let “Pretty Plots” Hide Bad Assumptions
Many “free layout” offers produce a visually impressive plan and color plot but skip the boring details. That is risky.
According to the DesignLights Consortium’s qualified products and technical requirements overview, utilities and large buyers focus on:
- LM‑79 test reports and IES files used in the calculations
- DLC listing status for incentive eligibility
- Operating hours and controls strategy documented for each space
This aligns with field experience: what de‑risks a project is not the color of the isolux map but how transparent the input assumptions are. When you receive a free layout, review it as if you were a reviewer:
- Is the LLF clearly stated and realistic for your environment?
- Are surface reflectances documented, not just left at defaults?
- Is there a controls narrative (sensors, schedules) or only a fixture count?
A layout that looks impressive but omits these points can leave you exposed if an inspector, client, or utility challenges the design.
How to Submit a Free UFO High Bay Layout Request That Engineers Respect
If you want your free layout to function as a serious design starting point—not just a sales sketch—treat the request like a mini design brief.
Step‑by‑step submission template
Use the following template to prepare your request. You can adapt this directly into an email or web form.
1. Project overview
- Building type: warehouse / manufacturing / gym / retail / other
- New construction or retrofit:
- Location (city, state):
- Ceiling and mounting heights (note slopes or mezzanines):
2. Drawings and photos
- Attach floorplan (PDF), plus CAD if available
- Mark racking, machinery, and any areas with different tasks
- Attach 3–6 representative photos
3. Lighting performance targets
- Storage areas: target ___ lux / fc
- Packing / inspection: target ___ lux / fc
- Assembly / detailed work: target ___ lux / fc
- Any internal standards (e.g., “no dark spots between racks”):
4. Surface finishes and environment
- Ceiling color/material (light/dark, painted/metal deck)
- Wall color/material
- Floor type (concrete, epoxy, etc.)
- Expected dirt levels and cleaning intervals
5. Controls and operating hours
- Hours per day and days per week
- Planned sensor types (occupancy, daylight)
- Any need for separate zones (e.g., aisles vs. dock vs. offices)
6. Retrofit baseline (if applicable)
- Existing fixture type (e.g., 400 W metal halide high bay)
- Quantity and layout description
- Approximate operating hours and any existing controls
Providing this level of detail up front usually reduces design iterations and produces a layout that can be handed directly to your electrical contractor or engineer of record for review.
Common Myths About Free Photometric Layouts—Debunked
Myth 1: “Average footcandles are all that matters.”
Many buyers fixate on a single average footcandle number. For aisles, racking, and sports areas, uniformity and vertical illuminance are often more critical. Research summarized in EN 12464‑1 and professional guidance (see the EN 12464‑1 overview) emphasizes not just average illuminance but also minimum values and glare indices. In practice, a layout with 25 fc average but good uniformity will feel safer and more comfortable than one with 35 fc average and severe hot spots.
Myth 2: “Catalog efficacy and L70 are all you need for lifecycle planning.”
Another misconception is that if a UFO high bay shows, for example, 150 lm/W and L70 > 50,000 hours in the catalog, you can treat that as guaranteed performance in your space. Real‑world experience and tools like DIALux show that if you ignore environment‑specific LLF, maintained illuminance over the first 5 years can drop 20–40% compared to initial predictions. Dust, ambient temperature, and maintenance practices all matter.
A realistic free layout explicitly includes LLF assumptions and may even show both initial and maintained illuminance values so you can plan re‑aiming, cleaning, or future retrofits.
Myth 3: “Once the fixtures are in, the job is done.”
Some project teams treat high bays as “install and forget.” Guidance from organizations such as NEMA on solid‑state lighting underlines that driver survivability, surge protection, and thermal management all affect long‑term performance. Sealed, non‑serviceable drivers concentrate failure risk into full fixture replacement. One of the hidden benefits of a good layout is that fixture counts and spacing can be planned with redundancy in mind—so if a few fixtures fail between maintenance cycles, light levels remain within acceptable ranges.
When a Free Photometric Layout Is Most Valuable
A free UFO high bay layout is particularly powerful when:
- Fixture counts exceed 10–20 units. At that scale, small errors compound into meaningful cost and performance differences.
- Ceiling heights are above ~18–20 ft. Beam control, spacing, and glare become much more sensitive to small changes.
- You need to justify a project to management or a client. A data‑driven layout with energy and rebate estimates turns a rough idea into a business case.
- You have safety‑critical tasks such as forklift traffic, crane operation, or detailed inspection.
As summarized in the DIALux documentation, a proper IES‑based layout with correct reflectances and LLF is often one of the few low‑cost ways to de‑risk both safety compliance and long‑term operating cost before placing a purchase order.
For task‑focused environments like automotive bays or fabrication shops, the article Why Mechanics Are Choosing UFO High Bays for Task Lighting illustrates how focused layouts can dramatically improve visibility on work surfaces.
Turning Your Free Layout into a Successful Project
A free photometric layout is the start of the design process, not the end.
To turn the layout into a successful project:
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Review assumptions carefully
- Check heights, reflectances, LLF, and controls in the assumptions sheet.
- Confirm they match your facility and cleaning practices.
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Validate against your internal standards
- Compare calculated illuminance and uniformity with your safety or production requirements.
- Adjust targets if needed before finalizing fixture counts.
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Coordinate with electrical design
- Share the layout with your electrical contractor or engineer.
- Verify circuiting, panel capacity, inrush current, and any 0–10 V dimming requirements.
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Align with rebates and codes
- Use the layout’s fixture schedule and LLF assumptions to support rebate applications.
- Ensure selected fixtures meet relevant standards (e.g., DLC listing, UL/ETL safety standards, FCC Part 15 for EMI) and any local energy code requirements.
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Plan maintenance and monitoring
- Set realistic cleaning and inspection intervals based on environment.
- Consider keeping a small stock of spare fixtures or drivers to preserve uniformity if failures occur.
For projects in jurisdictions with advanced controls requirements (such as California), pairing your photometric layout with an understanding of zoning and sensor placement—covered in Title 24 Controls for Warehouse High Bay Lighting—can significantly smooth inspections and approvals.
Key Takeaways
- A free UFO high bay photometric layout can be a serious engineering tool when it uses LM‑79‑based IES files, realistic LLFs, and clearly documented assumptions.
- The quality of your input data—heights, reflectances, tasks, and controls—is the single biggest factor in how accurate the layout will be.
- Focusing only on average footcandles is a mistake; uniformity, vertical illuminance, and glare often matter more to users and safety reviewers.
- Utilities and large owners pay close attention to LM‑79 reports, DLC status, operating hours, and controls strategy, not just pretty color plots.
- Treat the free layout as an opportunity to de‑risk safety, energy, and maintenance decisions before committing to hardware.
With the right inputs and expectations, a free UFO high bay photometric layout becomes an integral part of your design process—bridging the gap between catalog specs and real‑world performance on your warehouse or factory floor.
Safety & Compliance Disclaimer
This article provides general technical information about lighting design and photometric layouts. It is not a substitute for professional engineering, electrical, or safety advice. Always consult a qualified lighting designer, electrical engineer, or licensed electrician who is familiar with your local building codes, electrical regulations, and safety requirements before finalizing a lighting design or performing any installation work.
Sources
- IES LM‑79‑19 – Approved Method: Optical and Electrical Measurements of Solid‑State Lighting Products
- IES LM‑63‑19 – Standard File Format for the Electronic Transfer of Photometric Data
- DIALux – Lighting design made easy
- DesignLights Consortium – Qualified Products List and SSL Technical Requirements
- EN 12464‑1: Light and lighting – Lighting of work places – Indoor work places
- NEMA LSD‑80‑2015: Guidelines for Solid State Lighting
- AGi32 – Luminaire data and calculation methods
- IES – Lighting Handbook and technical resources