How to Bid a Window Replacement Job

Bid window replacement per window — it's how homeowners compare bids and how your crew thinks about the day. The 2026 US range: $400–$800 per vinyl double-hung installed (the most common job in America), with the national average around $600–$900 per window installed. Whole house: 10 windows in vinyl $5,000–$9,000, fiberglass $8,000–$14,000, wood/clad $12,000–$20,000+. Full-frame adds 30–50% over insert. The bid that wins isn't the cheapest — it's the one that proves you opened every window, measured every opening, and itemized the trim, disposal, and permit the low bidder “forgot.” See the full homeowner cost breakdown in our cost to replace windows guide.

2026 installed per-window prices by type

Installed prices per window, 2026 US range, consistent with our window cost guide. Insert/retrofit installation (new window in the existing frame) is the baseline; full-frame adds 30–50%.

Material is the single biggest lever — vinyl to wood roughly doubles the job. Present material tiers side by side on every bid: the vinyl column, the fiberglass column, the wood column. Clients comparing three bids choose the one that teaches them something, and the tiered presentation makes your per-window number look like a choice, not a cost.

Insert vs. full-frame: the bid-defining choice

Get this call right on every opening, and note it on the bid itself — clients comparing quotes notice which contractor actually classified their windows:

Bid insert by default; sell full-frame where the inspection justifies it. The tell-tale signs: soft or discolored wood at the sill (probe it with a screwdriver — if it sinks in, that's your photo), visible daylight around the frame, or windows painted shut for a decade. Full-frame is also the honest call when the client wants a different window size or style — inserts can't change the opening.

The per-window bid structure

Every window bid is the same seven lines. Build them for each opening, then roll up:

Present the per-window installed price, the line-item breakdown, and the whole-house total with a visible 10–20% multi-window incentive. Three numbers, three reasons to say yes: the unit price is comparable, the breakdown is honest, and the bundle rewards booking everything now.

Worked example: the 10-window vinyl house

Put the structure to work on the most common job in America — ten vinyl double-hung inserts. At a mid-range $650/window installed, the units-and-labor core is $6,500. Then the visible lines: interior trim and exterior capping at $75–$150 per window adds $750–$1,500; disposal at $25–$50 per old window adds $250–$500; a permit ($50–$300) where required; and lead-safe RRP procedures at $100–$200 per window if the house is pre-1978. A clean, fully itemized bid lands around $7,500–$9,000 — right in the $5,000–$9,000 whole-house vinyl band — with every dollar accounted for. Show the 10–20% multi-window incentive against a per-window rate and the client sees exactly what booking the whole house saves them.

Reading the house before you price

The openings set the product; the house sets the labor. Walk these before you finalize any number:

• Access and staging: second-story openings need ladder or staging time — budget ~15–25% extra labor on those windows and say so on the bid. Note shrubs, decks, and AC condensers blocking exterior access.
• Interior protection: furniture moves, drop cloths, and floor protection on every window. It's real time — and the crew that protects the house gets the referral.
• Alarm sensors and smart hardware: window sensors, wired alarms, and integrated blinds must be disconnected and reconnected. Ask who handles the alarm company — a dead sensor is your callback.
• Lead paint (pre-1978): decide during the walkthrough, not the install. RRP containment, cleaning verification, and documentation at $100–$200/window go on the bid as their own line.
• Structural red flags: sagging headers, water stains below sills, and spongy exterior sheathing mean the full-frame scope may grow once opened. Bid an allowance for structural surprises — never fixed blind.

Plan the crew day: scheduling math

A two-person crew installs 10–15 windows per day on insert work and 4–8 per day on full-frame. Schedule from those numbers and you stop promising one-day jobs that take two:

Add a half day for interior trim and paint touch-up if that's in your scope — it's the work clients see up close, and rushing it undoes a perfect install. And remember the lead time: windows are manufactured to your measurements, typically weeks out, so the deposit (10–30%) and a realistic install date go in the contract together.

Measuring protocol: 3 widths, 3 heights, no guessing

Wrong measurements are the most expensive mistake in window work — the unit is custom-made and non-returnable. Follow this protocol on every opening:

1. Measure width three times — top, middle, and bottom of the existing frame interior. Record all three.
2. Measure height three times — left, center, and right. Record all three.
3. The shortest measurement governs. Order from the smallest width and the smallest height; the install gets shimmed square, never forced.
4. Diagonal check: measure both diagonals of the opening. If they differ by more than 1/4 inch, the opening is out of square — flag it for a harder install or a full-frame conversion.
5. Jamb depth: confirm at least 3 1/4 inches of depth for an insert to seat into. Shallow jambs mean a different product or a full-frame build-out.
6. Note the rest: crank clearances, blind and curtain hardware, alarm sensors, exterior obstructions (shrubs, hose bibs, AC condensers), and which windows are second-story.

Put the measurements on the bid itself, per opening. It proves you were thorough, it protects you if an opening is out of square, and it's the first thing a manufacturer rep asks for when a unit arrives wrong.

Glass and option upsells

• Double-pane Low-E with argon: the 2026 standard — make it the baseline for every bid, not an upgrade.
• Triple-pane (+$100–$200/window): worth it in cold climates (Zone 5+) and for noise near highways or airports. Sell with U-factor numbers, not adjectives.
• Laminated glass (+$150–$300/window): security, storm protection, serious sound dampening — an easy upsell on ground-floor street-facing windows.
• Tempered glass: required by code near doors, in bathrooms, and for large low windows. Not optional where it applies — know your local code and quote it before the inspector does.
• Egress windows: bedrooms need code-compliant egress sizing. If the existing window doesn't meet it, the replacement is your moment to fix it — and a full-frame line item.
• Grids, colors, and interior finishes: low-effort margin on the unit order. Never leave them off the options list.

Federal tax credits and utility rebates for efficient windows change year to year — check energystar.gov and the client's utility before quoting, and put any rebate math on the bid as a separate line so the gross price stays honest.

Walk-away minimums

Not every job deserves your crew. Set these floors and hold them:

• Single-window minimum: one window at your full per-window rate plus a trip charge — a lone replacement still costs you a site visit, ordering, and scheduling.
• Whole-house incentive cap: discount 10–20% for the bundle, and stop there. Below that you're donating the efficiency, not sharing it.
• Deposit floor: never take less than the unit order cost. Custom windows with no deposit is a liability, not a sale.
• All-full-frame houses: if every opening needs full-frame, that's a premium job — price the carpentry honestly and walk if the client wants insert pricing for full-frame work.

Build your standard estimate on the contractor estimate template so minimums, deposits, and line items appear the same way on every bid — consistency is what lets you hold the floor without arguing about it.

The quoting process, step by step

1. Walk every window. Open it, check the sill with a screwdriver, look for fog between panes (seal failure), and photograph every problem. Painted-shut, rotted, or fogged units change the scope — find them during the estimate, not the install.
2. Classify insert vs. full-frame per opening. Mark it on the bid. Mixed houses are normal — quote each opening honestly.
3. Measure per protocol. Three widths, three heights, shortest governs, 1/4-inch diagonal check, 3 1/4-inch jamb depth. On the bid, per opening.
4. Spec material tiers. Vinyl, fiberglass, wood/clad side by side with glass options. The tiered presentation is the close.
5. Build the seven-line bid. Unit, labor, trim/capping, disposal, lead-safe where applicable, permit, deposit — then the per-window total and the whole-house bundle price.
6. Take 10–30% at signing. Windows are special-ordered with long lead times; the deposit protects your material order and commits the client.
7. Quote the same day you measure. Run the count through the window replacement calculator and send the quote from the driveway. Same-day quotes close at roughly double the rate of next-day ones.

Costly mistakes to avoid

• Quoting without opening every window. Painted-shut, rotted, or fogged units change the scope — find them during the estimate, not the install.
• Ignoring lead paint rules. Pre-1978 means EPA RRP compliance: certified procedures, containment, documentation. The fine for skipping it runs $40,000+ per day. Price the $100–$200/window in.
• Burying disposal and trim. They're real costs; hiding them just makes your bid look padded when the client finds out.
• Promising energy savings you can't quantify. “Up to 25%” on the window portion of the bill is honest; “cut your bills in half” is a lawsuit.
• One-size-fits-all glass. Street-facing gets laminated, cold climate gets triple-pane — spec the glass to the orientation.
• Skipping the final walkthrough. Open, close, and lock every window with the client present. Ten minutes prevents ten callbacks.

DIY vs. hiring a pro

A skilled DIYer can handle a ground-floor insert on a square opening — the process is straightforward when nothing is wrong. Where DIY goes sideways: out-of-square openings, full-frame work (flashing and water management are unforgiving), second-story ladder work, lead-paint homes, and the measurement itself — one wrong number and the $600 unit doesn't fit, with no return. Your honest pitch: “the window is custom-made to my measurements, and my warranty covers the install and the seal.” Most homeowners do the math on one ruined unit and hire the pro.

Do you need a permit to replace windows?

For insert/retrofit replacement: generally no — you're not opening the wall envelope. For full-frame replacement: yes in many jurisdictions, because the framing, flashing, and weather barrier are exposed and inspectable. Permit fees run $50–$300 in the 2026 US range. Pre-1978 homes add the EPA RRP lead-safe layer on top of any permit question. Put the permit on the bid as your line item and pull it yourself — “the other guy didn't mention a permit” is not a defense at inspection. When in doubt, check your municipality before you quote.