One sash. That's what it came down to.
Fourteen windows on a 1920s foursquare, three days of work, crew off the job by Thursday afternoon. Everything in, everything caulked, homeowner happy. Except the upstairs bedroom double-hung came in with a bottom sash a quarter-inch narrow — supplier's fault, not yours — and your lead installer shimmed it, made it work temporarily, and wrote "reorder bottom sash" on the back of a receipt.
That receipt went into the truck door pocket. The reorder got called in eleven days later when the homeowner emailed to ask. The replacement sash arrived four weeks after that. By then the installer who knew the job was on a different crew, the homeowner had stopped answering, and the $4,800 balance sat in your receivables aging report next to two other jobs that were also, technically, finished.
The job was 95% done in three days. The last 5% took four months.
Why the last 5% is the expensive part
Every window contractor understands the economics of the first 95%. You've priced the labour, you know your install times, you know what a crew costs per day. That part of the business is measurable and most owners manage it reasonably well.
The last 5% has no schedule, no crew assigned, and no line on the job cost sheet. It's a screen, a missing grid, a piece of capping that needs redoing, a signature, a permit sign-off. Each item is worth maybe twenty minutes of labour. Each one holds up a payment of several thousand dollars.
Worse, these items don't behave like work — they behave like admin. They get handled between other things, by whoever remembers, with no owner and no deadline. So they don't get handled.
Here's what's actually going wrong, in the order it tends to bite.
Mistake 1: Punch list items live in someone's head
Ask your lead installer what's outstanding on the Harrison job and you'll get an answer. Ask him next Tuesday, after two more installs, and you'll get a different one.
Window punch items are small and numerous: a screen that got bent in transit, a lock that binds, a bit of interior trim the crew didn't have the right stain for, a missing balance cover. On a fourteen-window job you might have five of these. None of them feel worth writing down at the time because the crew fully intends to sort them out on the way back from the supply house.
They don't. And the homeowner remembers every single one.
The fix isn't complicated, but it has to be mandatory: nothing leaves the site without a written punch list, photographed, attached to the job, visible to the office before the truck pulls away. If your crews are recording outstanding items on paper that then rides around in a van, you don't have a punch list — you have a rumour.
This is the specific thing job management software should be doing for you. In ExteriorPro, punch items get logged against the job from the phone on site, with photos, and they show as open tasks on the job record until someone closes them. The office knows the job isn't finished before the homeowner has to tell them.
Mistake 2: Nobody owns the reorder
A wrong-size sash, a cracked IGU, a grid pattern that doesn't match the order — these are supplier issues, and supplier issues are where jobs go to die.
The problem is ownership. The installer discovers the defect. The office places the reorder. The supplier ships it. Someone schedules the return trip. That's four handoffs, and at every one the item can stall with each party assuming someone else has it.
Pick one person who owns every supplier claim from discovery to installation. Not "the office" — a named person. Then give them a standing reorder log: job, item, date discovered, date ordered, promised date, actual arrival, date installed. Review it weekly. Anything past its promised date gets a phone call that day.
Suppliers respond to contractors who chase. If your reorder log shows three items sitting six weeks past promise, that's not a supplier problem anymore. That's your process.
Mistake 3: The return trip has no slot in the schedule
You'd never run an install without scheduling it. But the twenty-minute trip to hang two screens? That gets fitted in. Somewhere. Sometime.
Return trips are the single biggest reason finished window jobs stay open. They're too small to justify a crew day, too scattered to batch efficiently, and they compete with revenue work that always wins.
Two things actually work here.
Book a standing punch day
Half a day a week, same day every week, one person or a two-man crew doing nothing but return visits. It goes on the schedule like any other job. The cost is predictable and you'll find it's cheaper than you feared, because you're batching trips by geography instead of making one-off runs across town.
Make the return trip part of the original job, not a new one
Schedule it the moment the punch item is logged. If the sash is four weeks out, book the return visit for week five and let it sit on the calendar. You can move it. What you can't do is remember to create it.
Mistake 4: The completion form isn't signed at the end — it's chased later
The certificate of completion, the sign-off sheet, whatever you call it — if the homeowner doesn't sign it before your crew leaves, your odds of getting it signed drop sharply with every day that passes.
Partly that's logistics. Mostly it's leverage. The moment the truck is gone, the homeowner has no reason to hurry, and any lingering irritation about sawdust on the carpet has time to grow into a reason to withhold.
Get the signature on site, on a phone or tablet, before the crew loads up. If there are open punch items, the form should say so explicitly — "installation complete, outstanding: two screens, bedroom sash reorder" — and the homeowner signs off on the work that is done. That distinction matters. It converts "the job isn't finished" into "the job is finished except for these three named items," which is a completely different conversation when you invoice.
Digital sign-off attached to the job record, timestamped, with photos, kills most of the disputes that turn into 90-day receivables.
Mistake 5: The final invoice waits for "everything"
This follows directly from the last one. If your billing rule is "invoice when the job is complete," and a $60 screen is holding up completion, you have just made a $60 part responsible for a $4,800 payment.
Restructure the milestones. Deposit, delivery, substantial completion, punch completion. Bill the substantial completion milestone when the windows are in and operating — that's the bulk of the value delivered — and hold back a defined retainage against the punch list. Say 5%, or a flat figure that covers the outstanding work with a margin.
Write it into the contract so it isn't a negotiation later. Homeowners accept it readily when it's explained up front: you pay for the windows that are installed, you hold a small amount until the last details are done. It's how commercial work has operated forever.
The added benefit is that the retainage gives the homeowner a reason to let you back in to finish, which is more than you get when you've already been paid in full.
Mistake 6: Permits and inspections get treated as someone else's problem
Not every window job needs a permit, but a lot more of them do than get one — egress-related replacements, structural openings, anything in a historic district, anything where the local jurisdiction has decided replacement windows are its business.
The failure pattern is consistent. The permit gets pulled, the work gets done, and the final inspection never gets scheduled because the crew has moved on and the office assumes it happened. Six months later the homeowner is selling the house, the open permit shows up in the title search, and you're getting a call from a real estate agent about a job you'd forgotten existed.
Treat the inspection as a scheduled task on the job, assigned to a person, with a due date. Open permit, open job. It's that simple, and it's the kind of thing that quietly follows you around for years if you let it.
The same applies to lead-safe documentation on pre-1978 homes. The paperwork has to be retained, and the time to file it properly is the day the job closes, not the day an inspector asks.
Mistake 7: Nobody reviews open jobs on a fixed schedule
Every mistake above is survivable in isolation. What makes jobs sit open for months is that nothing in your week forces you to notice.
Work-in-progress is invisible by nature. The install happened, it felt like a success, the crew moved on, and the job quietly falls out of everyone's attention while remaining open on the books. Nobody wakes up and thinks about the Harrison job. It just sits there, aging.
Put a fixed weekly slot in the diary — thirty minutes, same time — and go through every job that is past its install date and not yet closed. For each one, three questions: what's outstanding, who owns it, when is it happening? If any answer is vague, it becomes an action item with a name and a date.
Run this for a month and you'll be surprised how many jobs you're carrying. Run it for a quarter and the number will drop, because the meeting itself changes behaviour — crews start closing things out properly when they know the list gets read aloud every Monday.
Software helps here in an unglamorous way. If your open jobs, their punch items, their outstanding balances, and their scheduled return visits are all on one screen, the review takes twenty minutes. If they're spread across a whiteboard, a text thread, a filing cabinet and your accounting package, it takes two hours and you'll stop doing it by February. ExteriorPro puts job status, tasks, photos, sign-offs and invoices on the same record for exactly this reason.
What good looks like
A window job that closes cleanly follows a pattern: punch list written and photographed before the crew leaves site, completion form signed on the spot with outstanding items named, substantial-completion invoice out the same day, return visit already on the calendar, reorder logged with an owner and a promised date, permit inspection scheduled, and the whole thing reviewed weekly until it's closed.
None of that is difficult. All of it is boring. That's precisely why it doesn't happen unless the system makes it happen.
The contractors who collect fast aren't better installers. They just don't let a screen hold a five-figure invoice hostage for four months.
Ready to get organised?
ExteriorPro is built for exterior contractors — job tracking, punch lists, scheduling, sign-offs and invoicing on one record, so jobs close when the work is done.
Start your free 30-day trial No credit card required. Cancel anytime.