Commercial and HOA
How to read a cheap exterior bid: line items, exclusions and substitutions
The gap between two exterior estimates is almost never the same product at two prices. It is scope: install method, opening prep, flashing, finish, and what the exclusions page quietly removed.
- Read in this order
- Exclusions, then the substitution clause, then the line items
- Priceable spec
- Manufacturer, series, operation, glass build-up, certified numbers
- Biggest hidden gap
- Install method and opening prep, per opening
- Warranties
- Two of them: manufacturer product, contractor labour
Start here
Why two bids on the same house are rarely the same scope
Most of the time the cheap bid is not dishonest. It is a different job.
A homeowner hands us two estimates and asks which one is real. Nine times out of ten neither is wrong: they price two different pieces of work. One is an insert unit dropped into the frame already in the wall. The other goes back to the rough opening, sets a sill pan, flashes the jambs and head into the weather-resistive barrier and rebuilds the interior return. Both print the same sentence: replace eleven windows.
What follows is the order we read somebody else's bid in. Exclusions page first, substitution clause second, line items last, because the first two decide what the third one means.
Line 1
The product line, the series and the glass package
"Vinyl, double pane, low-E, installed" is a category. It is not a specification.
A window line that can be priced names six things:
- Manufacturer and series. One manufacturer lists three vinyl series with different frame depths, chamber counts, sash profiles and hardware, and all three are honestly called vinyl double pane.
- Operation type, per opening. A casement closes against a compression gasket; a slider runs past a brush seal. Swapping one for the other moves the air-leakage number.
- The glass build-up. Lite count, which low-E coating, which glass surface it sits on, the spacer material, and whether the cavity is gas filled.
- Grids. None, between the glass, or applied to the surface.
- Safety glazing, called out per opening rather than assumed.
- The NFRC-certified numbers (U-factor, solar heat gain coefficient, visible transmittance and air leakage) for that exact configuration.
That last line is the quickest test on the page. Certified ratings are published per configuration, so the grid pattern, the spacer and the size all move them. One U-factor quoted across eleven different windows came off a brochure.
Line 2
Insert or full frame, and why the totals do not compare
An insert keeps the existing frame in the wall and lands the new window inside it. Faster, leaves the trim alone, and inherits everything behind that old frame, including flashing somebody else installed in 1994. A full-frame replacement removes the unit back to the rough opening, sets a sill pan, laps the jamb and head flashing into the barrier, then rebuilds the finishes. More labour, and the only version in which the opening itself gets corrected.
Mixed scopes on one house are normal. The defect is a bid that does not say which method it priced: if one estimate is an insert and the other is full frame, the cheaper number is buying less wall, and the page will not tell you that.
On a siding bid the same question is the substrate: cladding over the existing, tearing off to sheathing, or tearing off plus replacing sheathing. Three jobs, one description.
Line 3
Opening prep, and the soft sill nobody priced
Trim comes off and the sill is punky. That is a Tuesday, not a catastrophe.
Two honest ways for that possibility to appear on an estimate:
- A written unit price. Sill replacement per lineal foot, sheathing per sheet, framing repair per opening. Agreed before anybody found the damage, and therefore before anybody had leverage.
- A stated allowance carried in the total and reconciled at the end, with the unspent balance returned.
The third option is silence, and silence becomes a change order on the morning the wall is open. Ask for the documentation trigger too: a photograph and a location required before any additional work is authorised.
Line 4
The water-management details that never get itemised
This is where a cheap install is genuinely cheap, because none of it is visible once the crew has gone.
An opening is a hole punched in a water-shedding surface, and the assembly around it sheds in shingle-lap order: sill first, jambs over the sill, head flashing over the jambs, barrier over the head. Reverse one lap and the joint becomes a funnel pointed at the sheathing.
The sill pan is the piece that gets skipped, because it is buried before anyone sees it. It wants a back dam and end dams so water reaching the sill drains outward instead of running down the framing. Sealant behind the nailing flange goes at the jambs and head, and is deliberately left off the sill so the pan can drain. A crew that beads all four sides is being thorough and is building a bathtub.
On siding the equivalents are kickout flashing where a roof edge dies into a wall, the clearance the manufacturer specifies above roofs, decks and grade, and joint flashing behind butt joints. All of it is printed in the installation instructions, and all of it is what the material warranty is written against. None of it appears as a line item. Ask about it in words anyway.
Line 5
Finish work, containment and haul-off
A bid can be lower simply because its scope stops at the exterior face of the wall.
- Interior. Drywall return, casing, sill and stool, sealant and paint, and who paints it.
- Exterior. Stucco returns cut, patched, textured and coated to match; brick mould, trim wraps and colour-matched sealant.
- Protection. Floor covering, furniture sheeted, dust control inside the room and not only outside it.
- Containment. On housing built before 1978 the federal renovation, repair and painting rule governs how the work area is contained and cleaned. A bid carrying it and a bid ignoring it are not comparable.
- Haul-off. Disposal of the old units and cladding, and whether the dumpster is inside the total.
Line 6
Two warranties, not one
The manufacturer's warranty covers the product. The labour warranty covers the installation and is written by the contractor, so its term, scope and exclusions are whatever that contractor decided to type. Four questions get the real shape of it:
- How long does the labour warranty run, and does anything carry a shorter term (glass, screens, hardware, finish)?
- Does the product warranty transfer, and does the transfer carry a deadline or a fee?
- Does the product warranty require registration, and who files it?
- Who takes the service call in year six, and what do they need to open a claim?
Manufacturer terms belong to the manufacturer, so we hand over their document rather than paraphrase it.
The clause nobody reads
Substitutions, and the words "or equal"
Near the signature line sits a paragraph reserving the right to substitute materials of equal or better quality. It exists for real reasons (a colour discontinued, a series superseded, freight on a special-order size), and it is the easiest place on the page for a bid to stop meaning what it said. The fix is not to strike it, but to require that any substitution be identified in writing before it is ordered, with the replacement's certified numbers set beside the original's. Equal is a claim. The label is evidence.
The comparison sheet
Putting two bids on one page
One column per bidder, one row per line.
- Manufacturer, series and frame material
- Operation type and glass build-up, per opening
- Certified U-factor, SHGC (how much of the sun’s heat gets through), visible transmittance and air leakage
- Installation method, per opening
- Sill pan, flashing and barrier tie-in
- Interior and exterior finish, and who paints
- Hidden-condition unit prices or a reconciled allowance
- Containment, haul-off and disposal
- Labour warranty term, product warranty transfer, and who registers
- Lead time as the manufacturer gave it
A row blank on one bid is not a saving. It is a question. Fill the blanks and the totals usually move toward each other; whatever gap survives is the part you can actually decide on.
When the bids are level and the choice comes down to the window itself, our page on frames, styles and glass packages sets them out in detail.
While you are holding two bids
Questions we get before anybody has signed anything
It should name the manufacturer, the series, the frame material, the operation type, the glass build-up, and the NFRC-certified U-factor, solar heat gain coefficient, visible transmittance and air leakage for that exact configuration. Ratings are certified per configuration, so one U-factor quoted across a whole house of different windows came off a brochure rather than off a label.
You do not compare the totals, because they are not the same scope. An insert keeps the existing frame and lands the new unit inside it, which is faster but inherits whatever flashing is already there. A full-frame replacement goes back to the rough opening, sets a sill pan, flashes the jambs and head into the weather barrier and rebuilds the finishes. Ask each bidder to price the method the other one quoted.
It is money carried in the contract for damage nobody can see until the wall is open, such as a soft sill or wet sheathing. Three sentences keep it honest: unit prices for the common repairs, a photograph and a location required before extra work is authorised, and reconciliation at the end with the unspent balance returned.
Next step
Send us the bid you are already holding for a second read
Include the exclusions page and the substitution clause, and we will read the pages in the order above and tell you which rows of the comparison sheet are blank. That is a conversation, not a sales call, and it does not commit you to getting a number from us. Fill the blanks and the totals usually move toward each other.
- Every opening measured before anything is quoted
- The estimate names the series, the glass package and the certified numbers
- Unit prices for hidden conditions agreed before the wall is open
Prefer to talk it through? The shop line is (775) 391-8487, Monday to Friday, 9:00 AM to 4:00 PM.
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