We’re on commercial job sites every single day and we see all kinds of errors, lapses in judgement and outright bone-headed mistakes, but we’ve narrowed them down to the 5 most common and costly that we see on a somewhat regular basis. Keep in mind that commercial lighting decisions directly affect safety, productivity, brand perception, and operating cost so any error can create problems and ruin a contractor’s reputation.
Mistake 1 — Choosing lighting solely based on upfront cost
Choosing light fixtures based only on the purchase price of the products and not performance characteristics usually leads to higher operating expenses and faster obsolescence.
Why it’s a mistake
– Low initial cost often means lower efficiency, shorter lifespan, and inferior components resulting in higher energy and maintenance costs.
Typical impacts
– Increased electricity bills and more frequent replacements.
– Poor warranty coverage and higher total cost of ownership.
Fixes and best practices
– Evaluate total cost of ownership (purchase + energy + maintenance + disposal).
– Use lifecycle cost calculators and compare lumen-per-watt and rated lifetime (L70 or L90).
– Favor fixtures with robust warranties and high-quality drivers and thermal management.
Mistake 2 — Overlighting or underlighting spaces
Incorrect illuminance levels harm comfort, productivity, and energy efficiency.
Why it’s a mistake
– Overlighting wastes energy and causes glare; underlighting reduces task performance and safety.
Typical impacts
– Visual discomfort, higher HVAC load from excess heat, and noncompliance with standards.
Fixes and best practices
– Specify illuminance targets based on task and applicable standards (e.g., ASHRAE/IES recommendations).
– Use layered lighting: ambient, task, and accent. Provide dimming or zoning to adapt levels.
– Conduct a lighting audit and use photometric layouts during design.
Mistake 3 — Ignoring color quality and color temperature
– Poor color rendering and incorrect correlated color temperature (CCT) degrade appearance and functionality. Mixing different color temperatures in a room gives a very displeasing visual effect.
Why it’s a mistake
-Low CRI makes merchandise, finishes, and skin tones look unnatural; wrong CCT affects mood and circadian alignment.
Typical impacts
– Reduced visual appeal in retail, altered appearance of materials, and negative effects on occupant alertness or sleep cycles.
Fixes and best practices
– Specify and install products with CRI ≥ 80 for most commercial spaces; CRI ≥ 90 for retail, galleries, and color-critical work.
– Choose CCTs appropriate to use: warmer CCTs (2700–3000 K) for hospitality, neutral (3500–4000 K) for offices, cooler (4000–5000 K) for warehouses or detail work. Don’t mix CCT’s within the same space.
– Consider tunable white or circadian lighting where human performance and wellbeing are priorities.
Mistake 4 — Poor control strategy and lack of zoning
Fixed, “all-on” or poorly controlled systems waste energy and fail to support operational needs.
Why it’s a mistake
– Without occupancy sensors, daylight harvesting, scheduling, or dimming, lights run when they aren’t needed or at inappropriate levels.
Typical impacts
– Elevated energy use, higher maintenance, and inability to adapt to changing needs or hours.
Fixes and best practices
– Implement occupancy/vacancy sensors, daylight sensors, and time-based scheduling.
– Use networked controls for zoning, scene setting, and remote monitoring.
– Deploy presets for different modes (open hours, cleaning, after-hours) and integrate with building management systems (BMS).
Mistake 5 — Neglecting maintenance and quality controls
Skipping proper quality inspections and ongoing maintenance reduces system performance, lifetime and puts the entire project at risk.
Why it’s a mistake
– Improper installation, untested controls, dirty fixtures, and lack of lamp/driver replacement plans lead to poor performance and lifetime.
Typical impacts
– Uneven lighting, flicker, nonfunctional controls, and substandard energy savings.
Fixes and best practices
– Qualified, inspected and maintained lighting systems: verify output, controls behavior, and scene operation at handover.
– Create scheduled maintenance: clean luminaires, check connections, replace failing components before end-of-life failure.
– Use performance monitoring tools and set KPIs for lighting energy per square foot.
Here’s a quick checklist you can implement to avoid these common commercial lighting mistakes:
– Always evaluate lifecycle cost, not just purchase price.
– Be sure to match illuminance and distribution to tasks and standards.
– Specify appropriate CRI and CCT for each space.
– Incorporate adaptive controls: occupancy sensing, daylight harvesting, scheduling.
– Inspect and test everything at installation and set a maintenance plan with monitoring.
Bear in mind that commercial lighting affects cost, safety, and perception. Addressing these five mistakes by focusing on lifecycle cost, correct illuminance levels, color quality, smart controls, testing and maintenance, delivers better performance, lower operating expense, and a healthier environment, not to mention happier customers!
