Install day is fast: 30 to 60 minutes per window for an insert replacement, so most homes with 10 to 15 windows are finished in one to two days. The part that takes time is before that — 4 to 10 weeks for custom units to be manufactured and delivered.
People plan around the wrong number constantly. They budget a week off work for the install and get blindsided by the eight-week lead time they were told about once, in passing, at signing.
The full timeline
| Stage | How long |
|---|---|
| In-home consultation and quote | 1–2 hours |
| Decision and contract | Yours |
| Final technical measure | 1 hour, usually a separate visit |
| Manufacturing and delivery | 4–10 weeks (1–3 for stock sizes) |
| Permit, where required | Days to weeks, usually parallel |
| Install: insert, per window | 30–60 minutes |
| Install: full-frame, per window | 2–4 hours |
| Whole house, 10–15 insert windows | 1–2 days |
| Whole house, full-frame | 3–5 days |
| Interior trim and paint touch-up | Same day to a week after |
| Inspection, where required | 1–2 weeks after |
Total, realistically: six to twelve weeks from signing to finished. Two of those days involve anyone in your house.
Why the lead time is so long
Replacement windows are built to your openings. Nobody stocks a 33 and one-eighth by 51 and three-quarter double-hung in your color with your specific low-E coating. The order goes into a production queue, gets built, gets glazed, and ships on a truck that serves a region on a schedule.
What stretches it:
- Custom sizes, which is nearly all replacement work
- Non-white frames. Color adds a step and often weeks
- Grids between the glass, obscure glass, tempered glass
- Impact-rated units, which have their own production lines and lead times
- Arched, round, or geometric shapes
- Peak season. Late spring through early fall is when everybody orders
If timing matters — you are selling the house, or a baby is due — ask for the current lead time in writing before you sign, and ask what the manufacturer's stock sizes are. Sometimes shifting one opening to a stock size cuts weeks off the whole order, because the order ships when the last window is ready.
Insert versus full-frame, and why it doubles the day
Insert (pocket) replacement: the old sashes and hardware come out, the existing frame stays, the new unit goes into the pocket, gets shimmed and squared, insulated at the perimeter, and sealed inside and out. Your interior trim and exterior siding are untouched. 30 to 60 minutes, and the room is livable within the hour.
Full-frame replacement: everything comes out down to the rough opening. Interior trim off, exterior trim and some siding off, old frame out, new flashing installed, new window set and fastened to the structure, then trim and siding rebuilt. Two to four hours per opening, plus finish work.
Full-frame is the correct choice when there is rot, when the existing frame is out of square, or when you want to change the opening size. It is not an upsell in those situations. It is the only way to do it right.
What actually slows a job down on the day
Second-story openings. Ladders, scaffolding, or a lift, and every material moves twice.
Rot discovered at the opening. Nobody knows what is behind the trim until the trim comes off. Budget a contingency. A rotten sill is a couple of hours and a couple hundred dollars caught early; a rotten header is a different conversation.
Old aluminum or steel frames that were installed with fasteners nobody makes tools for anymore.
Stucco and brick exteriors, which need careful cutting and proper re-sealing.
Painted-shut interiors on old wood windows, especially where the paint may be lead-based, which brings its own handling requirements and slows everything down for good reason.
Weather. Nobody opens six holes in the wall of a house during a downpour.
How the day actually goes
Crews work one opening at a time, or two if the crew is larger. Your house is never fully open — a single window is out for maybe twenty minutes.
What is expected of you: clear a three-to-four foot working path in front of each window inside, take down blinds and curtains, move furniture back, take pictures off the adjacent walls because there will be vibration, and put pets somewhere that is not the work zone.
What to expect from them: drop cloths, cleanup of the old units, and a walkthrough at the end where every window gets operated and locked in front of you. Do that walkthrough. Open and close each one, lock each one, tilt each one. Problems found on the day get fixed on the day.
When you should not be in a hurry
Do not accept a same-week install offer on a full-house job without asking what is in stock. Sometimes it is a legitimate cancellation slot. Sometimes it means you are getting whatever sizes are sitting in the warehouse, shimmed to fit your openings with more foam than is ideal.
Do not let anyone skip the second measure. The salesperson's numbers are for the quote. A technical measure by the installer, after the contract, is what the manufacturer builds to. Skipping it is how a $12,000 order arrives an inch short.
Do not schedule the interior paint for the day after. Caulk needs to cure, and you may want a week to notice anything that needs adjusting.
The one thing worth waiting for
If your quote comes back with a shorter lead time because a different glass package is in stock, look closely at what changed. Getting your windows three weeks sooner with a weaker low-E coating is a bad trade you will live with for twenty-five years. Our energy-efficient windows guide covers which label numbers actually matter.
Decatur IL Windows installs vinyl replacement windows, double-hung units, and energy-efficient glass packages across Decatur and Macon County in central Illinois, and we give you the real lead time at the quote rather than after the deposit. For pricing, see our new window cost guide.
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Related services in Decatur
Decatur IL Windows money pages — go straight to the service you need.
- Energy-Efficient Windows →
Decatur sits in a heating climate, and the specification most quotes push here gets one number backwards. They reach for the lowest solar heat gain the product line offers.
- Vinyl Windows →
Vinyl is the right material for most houses in this city, and the question that actually matters is not vinyl against something else. It is which vinyl, because in a staged job you have to be able to buy the same one again in four years.
- Double-Hung Windows →
The double-hung is what nearly every house here already has, and it is what will go back in. The decision that matters most is invisible from the street: which balance system holds the sash up, and whether the whole house ends up on one.
- Fiberglass Windows →
This page argues mostly against its own product, and the reason is arithmetic about your house rather than anything wrong with fiberglass. Pultruded fiberglass is the better frame.
- Wood and Clad Windows →
About 8,200 housing units in Decatur were built in 1939 or earlier, close to a quarter of everything standing. That stock came with wood sash, and on a surprising number of those houses the original sash is still the best window we look at all week.
Frequently asked questions
How long does it take to replace one window?
An insert replacement in a sound frame takes 30 to 60 minutes including interior and exterior sealing. A full-frame replacement, where everything comes out to the rough opening, takes 2 to 4 hours because trim, flashing, and siding all have to be rebuilt.
How long does it take to replace all the windows in a house?
Most homes with 10 to 15 insert replacements are done in one to two days. Full-frame work on the same house runs three to five days. The variables are window count, whether any are on a second story, and how much carpentry the openings need.
How long does it take to order replacement windows?
Four to ten weeks is normal for custom-sized units, and that is the biggest chunk of the whole project. Stock sizes can arrive in one to three weeks. Specialty items — impact-rated, obscure glass, unusual colors, arched tops — sit at the long end.
Can windows be replaced in one day?
Yes, and it is routine. A crew of two or three handles 8 to 12 insert replacements in a day comfortably. Anyone promising same-day for a full-frame job on a whole house is either bringing a very large crew or cutting the parts you cannot see.
Do I need to be home during window installation?
For the initial measure and the final walkthrough, yes. During the install itself you do not need to be present the whole time, but somebody should be reachable, because openings occasionally reveal rot or old framing surprises that need a decision.
Do replacement windows need a permit?
Often yes, and it varies by jurisdiction. Like-for-like insert replacements are sometimes exempt; changing the opening size, structural work, or impact-rated installations in coastal zones typically are not. Your contractor should handle it, and permit and inspection scheduling can add days to the timeline.
Local context
How this applies in Decatur, IL
Every article here is written from window work done in Decatur and Macon County in central Illinois, so the numbers reflect local labour, permit and material costs rather than a national average. Your own job can land either side of them depending on access, the condition of what is already there, and the materials you pick — a written order specification carried forward from one round into the next, a low-emissivity coated triple-track storm panel hung over sound original sash, constant-force stainless balances kept on one system across an entire house.
The way to turn any of this into a real answer is to have someone look at your actual situation. The free estimate is free, itemized and written down, with no deposit and no obligation. Call (844) 511-2320 or start on the Decatur IL Windows homepage.
Areas Decatur IL Windows covers
Decatur first, then the surrounding communities of Macon County in central Illinois. Each has its own page with local detail rather than a copy of this one:
- Forsyth, IL — Macon County, population 3,734
- Mount Zion, IL — Macon County, population 6,019
- Long Creek, IL — Macon County, population 1,261
- Harristown, IL — Macon County, population 1,310
- Warrensburg, IL — Macon County, population 1,110
- Argenta, IL — Macon County, population 913
Or jump to the full list of Decatur services.
More from the Decatur IL Windows blog
- Window Fogging Between Panes in Decatur, IL: Fix It?
Fogging between window panes in Decatur, IL — why the seal failed, glass-only repair cost, and the warranty most people never claim.
- Vinyl vs Fiberglass Windows for Decatur, IL Homes
Vinyl vs fiberglass windows in Decatur, IL — the real price gap, thermal expansion, and when the cheaper frame is the right call.
- Double-Hung vs Casement Windows for Decatur, IL Homes
Double-hung vs casement windows in Decatur, IL — why casements seal tighter, where double-hungs win, egress minimums, and which to pick room by room.
The Decatur IL Windows Team
Licensed window pros in Decatur, IL
Written by the Decatur IL Windows team — licensed, insured window pros serving Decatur, IL and the surrounding area.