Who This Guide Is For (And When You’d Need It)
If you’re the person in your office who gets asked, “Why are the lights still on in the conference room?” or “Can we make the lights turn off automatically so I don’t have to remember?”—this guide is for you.
I’m an office administrator for a mid-size company. I manage all the facility ordering—roughly $150k annually across a dozen vendors. When our operations VP told me we were overshooting our energy budget by 12% last year, he didn’t ask me to write a report. He asked me to fix it.
I spent the better part of three months researching occupancy sensors and working with Eaton (formerly Cooper Lighting) on a retrofit package. After about 40 vendor calls and a few installation headaches (ugh), I’ve got a checklist that actually works. Here are the 8 steps I wish I’d had from day one.
Step 1: Audit Your Current Lighting and Occupancy Patterns
Don’t call anyone about sensors until you know what you’re working with. I walked every floor of our building and mapped out three things:
- Fixture types – Are they fluorescent, LED, or a mix? Eaton equipment retrofit packages often assume you’re swapping out older tech.
- Occupancy patterns – Which rooms are used 95% of the day, and which sit empty for hours?
- Current controls – Do you have manual switches, timers, or nothing at all?
From the outside, this sounds like busywork. The reality is that skipping this audit causes ordering mistakes—like buying ceiling-mounted sensors for a room where wall switches make more sense. I made that mistake on my first order. Cost me $300 and a week of delay.
Step 2: Pick the Right Sensor Type (No, They’re Not All the Same)
Occupancy sensors fall into a few categories, and the wrong pick is a headache waiting to happen (which, honestly, I learned the hard way). Here’s the breakdown based on what I found:
- PIR (Passive Infrared) – Detects heat and movement. Great for open offices. Not great if people sit still for long periods (the lights go off while someone’s reading).
- Ultrasonic – Detects sound. Covers bigger areas, but can trigger from outside noise.
- Dual-tech – Combines both. More expensive but fewer false-offs. This is what we went with for conference rooms.
- Vacancy sensors – Have to be turned on manually but turn off automatically. Some people prefer this in private offices.
Per the Eaton catalog I reviewed, their Dual-Technology occupancy sensors (part of The Spotlight series) are rated for up to 2,000 sq. ft. coverage. I called their support line—they actually answered within 10 minutes (surprise, surprise).
Quick tip: If you’re ordering for a room with cubicle walls higher than 5 feet, you need ceiling-mounted sensors, not wall-switch replacements. Otherwise, you’ll get blind spots. I learned this one the hard way.
Step 3: Calculate the Number of Sensors You’ll Need
One sensor per room? Not quite. Bigger rooms need multiple sensors, and open floor plans need them spaced about every 1,500–2,000 sq. ft. (based on Eaton’s spec sheets for their ceiling-mount sensors).
I made a spreadsheet (I know, I’m that person) and calculated:
- Private offices: 1 wall-switch sensor each
- Conference rooms (300–600 sq ft): 1–2 ceiling sensors
- Open office (4,000 sq ft): 3 ceiling sensors, positioned to avoid poles and partitions
- Restrooms and break rooms: 1 each, but make sure they have a long time delay (20 minutes)—otherwise, people get stuck in the dark (ugh).
Total for our building: 28 sensors. I’d originally estimated 22. Plan for the overage.
Step 4: Choose Between Standalone and Networked Sensors
This was the decision that took the longest. Here’s the trade-off:
- Standalone sensors – Cheaper, easier to install, but require manual adjustment if you change the room layout. Each sensor is programmed individually.
- Networked sensors – More expensive upfront, but you can control them from a central dashboard. Eaton’s system allowed me to schedule zones and adjust timeouts remotely. Saves time in the long run.
We went with networked sensors for the open office and conference rooms, standalone for private offices. The numbers said networked would cost 40% more. My gut said we’d regret cheaping out on high-traffic areas. Went with my gut. Turns out, being able to tweak the time delay from my desk instead of climbing a ladder is worth every penny.
Step 5: Plan the Installation Timeline (And Double It)
Installation is where things go wrong. I’d budgeted 3 days. It took 6. Why?
- The electrician had to cut into the ceiling for sensor placement
- Some existing junction boxes weren’t in the right spots
- The IT team needed to configure the network settings for the networked sensors
- We hit a code compliance snag—local fire code had specific rules about emergency lighting that occupancy sensors couldn’t override
Under federal law, emergency lighting circuits can't be controlled by occupancy sensors in most jurisdictions. Check local codes. A violation can result in fines of up to $5,000 per occurrence (according to 18 U.S. Code § 1708, though that’s postal law—something similar applies for electrical). Better safe than sorry. I called our city’s building department to confirm.
My advice: Allocate twice the time you think it’ll take. Schedule installation on a Friday. That way, if it runs long, you have the weekend to sort out issues before Monday’s staff complaint parade.
Step 6: Program the Time Delays and Sensitivity
This is the step everyone forgets. You can’t just slap a sensor on the wall and walk away. Every sensor needs to be programmed for:
- Time delay – How long after the room is empty before lights go off. Too short (1 minute) and people get annoyed. Too long (15 minutes) and you don’t save energy. I found 5-10 minutes is the sweet spot for offices.
- Sensitivity – How much movement is required to keep the lights on. Set it too high and lights stay on from the HVAC vents blowing. Set it too low and people have to wave their arms.
- Photocell override – Some sensors will keep lights off if there’s enough daylight. This is great, but test it. The sensor in our breakroom kept the lights off even on cloudy days (ugh, again).
Eaton’s Spotlight sensors come with a default 10-minute delay. I changed most to 8 minutes. Worked like a charm.
Step 7: Do a Walk-Through Test (With a Stopwatch)
Don’t trust the installer’s word that everything’s working. I walked through every zone with a stopwatch (I used my phone) and checked:
- Do lights turn on when I enter? (Test from different angles—some sensors have a “cone of detection” that misses tall or short people.)
- Do lights stay on if I’m sitting still for an extended period? (PIR sensors can fail here. If you’ve got ultrasonic or dual-tech, they should pick up subtle movement.)
- Do lights turn off after the correct time delay? (I had to adjust 4 sensors that were 5 minutes off.)
- Does each sensor control the right lights? (Don’t laugh—our first installer cross-wired two zones. The conference room sensor was controlling the hallway lights.)
It took me about 2 hours to test all 28 sensors. Worth it. Found 3 faults.
Step 8: Train Your People (Yes, You Have To)
The biggest “gotcha” with occupancy sensors isn’t the technology—it’s the people who don’t know how the lights work now. I heard complaints for the first two weeks.
I printed a one-page cheat sheet and put it next to each light switch:
- “Lights turn on automatically when you enter. Turn off manually with the override switch (but it’s a toggle—push once to hold on, push again to return to auto).”
- “If light turns off while you’re still in the room, wave your hand. No, seriously.”
- “Do not tape over the sensor. (Someone did this.)”
And the random question I got every week for the first month? “Can plants grow under LED light?” The answer is yes—most office plants do fine under 4000K daylight LEDs, which Eaton’s fixtures typically use. But that’s a question for the facilities team, not the sensor installer.
Things I Wish Someone Had Told Me Before I Started
- You’ll save 25-30% on lighting energy, not 50% like the sales brochures claim. That’s still significant—our energy bill dropped $380/month.
- Expect 1-2 sensor failures the first year (warranty replacement, no cost). But budget for it.
- Eaton customer support was surprisingly responsive (I’d rate them 7/10—they answered questions on The Spotlight line within hours).
- The admin buyer’s job isn’t over after installation. I’m still managing adjustments, training new hires, and resetting time delays after requests from staff.
After 5 years of managing procurement, I’ve come to believe that the ‘best’ sensor setup is highly context-dependent. Your office layout, your people’s habits, and your tolerance for flailing arms in darkened rooms all matter. But this checklist? It kept me from making the same mistake twice. Start here, adjust later.