Just wrapped up the job I underbid last fall and somehow came out okay

Been on both sides of this one. A few years back I quoted a full exterior repaint on a two story stucco place and completly blanked on the second story trim. everthing above the first floor windows. My painter pointed it out the day before we started and my stomach dropped. I was light by roughly a third on labor.

I called the homeowner that same evening instead of sitting on it. Told her straight up I made a counting error on my end, showed her my math, and gave her two options. She could pay the difference in installments, or I could do the high trim at cost and eat my margin. She picked the installments and honestly respected me more for flagging it before I started cutting corners to claw money back.

What I changed after was simple. I now walk every exterior job with a paint marker and physically mark each item as I count it. Soffit runs, fascia, columns, everything. Sounds dumb but my eyes skip things when I am squinting at photos on a screen. The marker forces me to touch each one. One thing I would push back on from your post, walking the site is not just about catching scope gaps. Half the time I catch access problems, bad ladder set positions, overgrown hedges, a gate that will not open wide enough. Those things burn hours that never show up on drawings either.

I took the opposite path on a similar mess and it worked out okay, though it was pure panic at the time. Bid a restaurant interior repaint a few years back and forgot the whole ceiling grid was getting swapped, not just cleaned. I was maybe 40 percent light on labor. I never called the GC about it. Just ate it, worked my regular crew six days a week for five weeks, and did the ceilings myself on Saturdays to save the overtime. Here's the part nobody expects. That GC noticed. He knew what my bid was versus the other subs and he knew what we actualy put into the job. Six months later he handed me a tenant improvement package without me even bidding against anyone, and that job was profitable enough to wipe out most of the loss from the first one. I'm not saying that's the smart play. If I'd had a signed contract with a clear scope I prolly would have tried a change order like you did. But on a handshake deal with a GC I wanted a long relationship with, swallowing it quietly bought me something a negotiation never would have. Three jobs with him now and he sends me his takeoff spreadsheet before I even ask. Sometimes the loss is the price of admission.

Pretty new here and pretty new to bidding work in general. I do small deck repairs on the side and my version of this was forgetting dump fees and haul off on a quote, not scope stuff. Only a couple hundred bucks but it stung at my scale. Question though, you mentioned having someone else check your numbers before they go out, and I work solo so there's nobody. I've taken to writing the bid one day and reading it out loud the next morning before sending it. Catches dumb stuff weirdly often. Anyone else bid solo and have a trick for that?

That line about the estimator assuming you knew what you were doing is so true it hurts. My version of this was a big box store interior job where I missed an entire accent wall color band around the perimeter. Found out on day two and just quietly resequenced the crew to hide it. Ate the hours, never said a word, and it still bugs me that I didn't at least try what you did.

The thing that actually fixed my counting problem was a dumb $6 tally clicker from the hardware store. I used to count elevations and rooms on my fingers while scrolling plans, and my thumbs would lose track. Now every item gets a physical click and a mark on the printed sheet. My bid totals went up a bit and my losses basially stopped. Weirdly the cheap plastic thing did more for my margins than any estimating course I ever took.

Update: job's wrapped and the change order actually got paid without drama, so the whole thing landed way softer than I deserved. The reply from the guy who quietly hid his missed wall and ate the hours stuck with me, that could've been me if I'd stayed silent. Anyway, second pass on every takeoff is just how it works now. Anyway, moving on.