It Started With a 'Peacemaker' and a Wrong Number
I got the call on a Tuesday afternoon in September 2022. My tenant in unit 4 said a woman was standing in the hallway, flashing something at the doorbell camera. “Seriously,” she said, “she’s just standing there. Flashing.”
My first thought? Great. A peacemaker woman flashing. I’d been trying to find a vintage Colt Peacemaker part for a project, and I’d posted about it in a few forums. Somehow, my brain connected the dots to a Craigslist deal gone wrong. I assumed this was a seller trying to meet up. I was way off.
I drove over, half-expecting to see a Western movie prop. Instead, I found a confused woman holding a printed ad for a garage sale—not a firearm—waving it at the camera because the doorbell wasn't working. The whole thing was a misunderstanding. But it got me thinking: how many other things in this business do I misunderstand because I’m looking at them wrong?
That was the trigger. I started documenting every dumb mistake I made in my rental and renovation work. Not the big, obvious stuff. The small, costly ones. The kind where you’re staring at a $3,200 bill and thinking, “How did I not see that coming?”
Here are five of them—the ones that taught me the most.
Lesson 1: The Tape Measure Betrayal
“I ordered 50 new windows for a duplex. Half of them didn’t fit. The guy at Glass Doctor (ugh, the glass doctor company we used) said my measurements were ‘creative.’”
Everything I’d read about measuring for windows said the same thing: measure three times, cut once. Simple, right? In practice, I found that the conventional wisdom is a lie. The problem isn’t measuring three times. It’s how to read a tape measure correctly when you’re on a ladder, in a hurry, and the sun is in your eyes.
The mistake wasn’t the number. It was the mark. I was using a tape measure with a worn-out hook. On a 30-inch window, the hook slippage introduces about a 1/16-inch error. On paper, that’s fine. On a 50-window order where every single frame had shifted 1/8-inch due to settlement? That was a disaster. Half the windows were too tight, the other half had gaps I could stick a pencil through.
That mistake cost $890 in redo labor (we had to send a crew back to adjust frames) plus a 1-week delay on the entire project. The tenant’s new move-in date got pushed back. They canceled. Lost rent for two months while we waited for the new windows. Total tab: about $4,700. (Ugh.)
What I do now (the lesson): I use a digital tape measure for any order over 10 units. It’s not the accuracy that’s better—it’s the consistency. No hook slippage, no reading errors. The tool doesn’t cost much, but the process of verifying every single measurement with a second method (a laser if possible) has become my non-negotiable checklist item.
Lesson 2: The Garage Door Opener Remote That Wasn't a Remote
In March 2023, I had a tenant who lost their garage door opener remote. They wanted a replacement. I called our supplier (who also sells those umarex colt peacemaker parts online—weird combo, I know) and asked for a new remote for the model of opener we installed. The guy on the phone said, “Yeah, it uses the standard one.” So I bought it.
It didn’t work. I bought a second one, thinking I had a defective unit. That one didn’t work, either. I called the vendor back. He said, “Oh, you need the programmable remote. The standard one is only for the newer models.” The newer models were installed in 2021. Our building was built in 2020. The opener was from 2019. It wasn't new enough.
The total cost of the two wrong remotes? $72. The cost of the third, correct one? $45. The cost of my time driving back and forth, the tenant’s frustration, and the bad Google review they left? Priceless (in the worst way).
What I do now: I keep a digital log of every appliance model number, including the manufacture date. For garage door openers, I now program a new remote for the tenant before they move in, so I can test it. It adds 15 minutes to the turnover process but saves a ton of headache.
Lesson 3: The ‘Standard’ Pricing Myth
“I once took the cheapest quote for a foundation repair. The guy had a great story and a beat-up truck. He was also a terrible estimator. The final bill was 40% higher than the middle quote, and it took a month longer.”
I’m not 100% sure what the standard markup is for most contractors, but I can tell you this: the first quote is almost never the final price. Here’s something vendors won’t tell you: the lowest initial bid is often a loss leader to get their foot in the door. They’ll find the “problem” later and hit you with the real number.
Conversely, what most people don’t realize is that the highest quote isn’t always the best quality. I had a painter quote $8,000 for a duplex. The next quote was $5,500. I went with the $8,000 guy because I thought he was “premium.” The $8,000 guy used the same sherwin-williams paint as the $5,500 guy. The difference? The $8,000 guy padded his estimate with “project management” fees. The painting itself cost the same.
What I do now: I never take the first or last quote. I take the middle one, but I verify the scope of work. I ask, “What happens if you find rotten wood or a hidden pipe? Is that included in this price or is it a change order?” If they hedge, I walk. I usually get three quotes for anything over $1,000. For anything under $500, I just do it myself if I can.
Lesson 4: The $2,000 Tape Measure (Because It Was a ‘Decorative’ Repair)
This one still hurts. I had a beautiful old house with a French door that was sticking. The tenant said it was just the humidity. I believed them. I sent a handyman to sand the edge. He sanded it, it worked for two weeks, then stuck again. He sanded it again. It stuck again.
After the third sanding (October 2023), I finally took off the door. The frame was rotting from the bottom up. The “humidity” was actually a slow leak from the shower niche in the bathroom on the other side of the wall. That shower niche was installed wrong four years prior. The water had been soaking the floor joists, the subfloor, and then the door frame.
The repair cost? $2,000. The damage? Rotten subfloor, a ruined door, mold in the wall cavity. I could have fixed the leak for $200 four years ago if I’d known. The “decorative” issue turned into a structural one.
What I do now: The lesson wasn’t about the water leak. It was about symptoms vs. causes. If a fix doesn’t work the first time, I don’t try the same fix again and hope it works. I stop, investigate, and call a specialist (in this case, a plumber, not a handyman). I also use my tape measure to check for level on every doorframe during the annual inspection. If a door is suddenly out of square, it’s a red flag.
Lesson 5: The ‘Peacemaker’ Flash—and Why Context Matters
Back to the woman with the garage sale flyer. That peacemaker woman flashing moment was my biggest lesson of all. I had assumed I knew what was going on. I had a mental shortcut: “peacemaker” equals “gun,” “woman flashing” equals “gun seller.” I was so locked into my own narrative (I need the part) that I failed to see the reality (this is a lost person with a piece of paper).
This happens in business all the time. You see a “problem” and immediately jump to a conclusion based on your past experience. A tenant complains about a garage door opener remote? You assume it’s broken. But maybe the battery is dead, or they’re holding it wrong (yes, this has happened). A kitchen cabinet door is hanging crooked? You assume the hinge is broken. But maybe the whole cabinet is pulling away from the wall due to a stud issue.
What I do now: I’ve trained my team (and myself) to ask one question before we spend any money: “What else could this be?” We literally have a checklist for common problems. For a stuck garage door, it’s: battery? Track alignment? Sensor? Remote programming? We check the simplest, cheapest thing first. This one question has saved me thousands.
The Real Bottom Line
What was best practice in 2020 (measure twice, buy the cheapest remote, trust the first quote) may not apply in 2025. The fundamentals haven't changed—you still need accurate measurements and reliable vendors. But the execution has transformed. For me, that transformation came from five specific, documented, expensive mistakes.
The most valuable tool in my kit isn’t a laser level or a digital caliper. It’s the lesson log I started after the ‘Peacemaker incident.’ Every time I make a mistake—or nearly make one—I write it down. What was the trigger? What did I assume? What should I check next time?
I’ve caught 23 potential errors in the past 18 months using that log. The cumulative savings? Probably in the $8,000-$12,000 range. Not bad for a hobby that started with a wrong number and a woman flashing a piece of paper.
