A photometric plan is a technical lighting document that shows how light is distributed across a space.It is used by lighting designers, engineers, and code officials to verify that a lighting system meets required performance, safety, and visibility standards. Photometric plans are based on real fixture data (IES files) and calculated using professional lighting software.They are required for many commercial, industrial, and outdoor projects before permits are approved. This guide explains what a photometric plan is, what it includes, how it is created, and why it is required. What Is a Photometric Plan? A photometric plan is a drawing that visually represents light levels across a defined area.It shows how much light reaches the ground, floor, or working surface from installed fixtures. A standard photometric plan displays: Designers use photometric plans to adjust fixture spacing, optics, and quantities to achieve consistent and code-compliant lighting. Ready to optimize your lighting project with precision and efficiency? Click the button below to get started! Order Your Photometric Plan What a Professional Photometric Plan Includes for Permits A professional photometric plan is not just a lighting layout.It is a verified performance document used for approval and construction. A complete photometric plan typically includes: For outdoor projects, photometric plans also include: This level of detail is what cities, engineers, and contractors expect when reviewing a photometric plan. How Designers Create Photometric Plan Designers follow a structured process to create accurate and reliable photometric plans. 1. Understand the Space The first step is understanding the layout, dimensions, and use of the space.For outdoor projects such as parking lots or site lighting, scaled aerial images or CAD site plans are used. 2. Determine Lighting Requirements Designers define the required light levels based on: This includes target foot-candles, uniformity ratios, and glare limits. 3. Select the Right Fixtures Fixtures are selected based on: Each fixture’s photometric data (IES file) determines how light is distributed across the site. 4. Use Photometric Software Lighting software calculates how light spreads based on fixture placement and photometric data.This step produces the actual photometric plan. 5. Analyze and Adjust Results Designers review the results and adjust fixture spacing, optics, or quantities until performance targets are met. Which Software Is Used to Create Photometric Plans? Two of the most widely used lighting software tools are DIALux EVO and AGi32. Both programs use IES photometric data and produce code-compliant photometric plans when used correctly. DIALux EVO and AGi32 are widely used lighting software programs for designing and analyzing lighting plans. In practice, each tool serves a different type of user. As a result, they differ in several key areas. 1. User Interface First, DIALux EVO offers a user-friendly interface that designers can navigate easily, which makes it suitable for beginners. By contrast, AGi32 provides a more advanced interface and requires technical knowledge to operate effectively. 2. Calculation Capabilities In both cases, the software uses photometric technology to calculate light distribution within a space. However, AGi32 supports more advanced calculations. Because of this, designers can run more detailed simulations and perform deeper analysis. 3. Fixture Libraries In terms of fixture data, AGi32 includes a larger library of lighting fixtures, materials, and photometric files. Meanwhile, DIALux EVO provides a comprehensive library, but it offers fewer fixture options overall. 4. Pricing From a cost perspective, DIALux EVO is available as a free program. By comparison, AGi32 requires a paid license, with pricing based on the license type and selected features. How to read a photometric plan A photometric plan contains several key elements that designers and inspectors review. 1. Lighting Layout This shows fixture locations, mounting heights, and coverage areas.Designers position fixtures to achieve even illumination and avoid dark spots. 2. 3D Presentation 3D views help visualize how lighting will appear once installed. In addition, they are useful for coordination; however, they do not replace calculated results. One of the key benefits of a 3D presentation of a light plan is that it allows designers to see how lighting interacts with the space and other design elements, such as furniture or architecture. As a result, designers can identify potential issues early. In turn, this enables them to make necessary adjustments before installation, which helps prevent problems during fixture installation. 3. Calculation Points Calculation points show foot-candle values at specific locations.Designers typically space these points 10–20 feet apart based on project requirements. 4. Calculation Surface The calculation surface summarizes performance data for each zone, including: The maximum/minimum ratio indicates the overall distribution of lighting, with lower ratios indicating more uniform distribution and increased visual comfort. The average/minimum ratio shows how the least bright point differs from the average rating. When a Photometric Plan Is Required for Approval Designers require a photometric plan to verify lighting performance before installation. Common applications include: Without a photometric plan, reviewers often delay, reject, or require late redesigns of projects. Why the Photometric Plan is Important Photometric plans serve several critical purposes: They also help clients avoid costly revisions after installation. You can find some real-world case studies for the parking lot photometric plans in the following link. How Long Does It Take to Create a Photometric Plan? The time required depends on: Small projects may take a few hours.Large or complex projects may take several days. At Stetra Lighting, we typically deliver a professional photometric plan within 1 to 3 business days. For quick measurement of the lumens required of a particular space, feel free to use our lumen calculator. Final Thoughts A photometric plan is a critical tool for designing safe, efficient, and code-compliant lighting systems.Whether for a parking lot, warehouse, sports field, or commercial site, a properly prepared photometric plan ensures predictable performance and smoother approvals. If you are planning a new lighting project or upgrading an existing one, you can order a professional photometric plan directly through Stetra Lighting. If you like to upgrade or build from the start your sports terrain, parking lot, warehouse, or any other space with new lighting, you can order your photometric report by