Window schedule vs. elevations: reconciling the mismatch

If you estimate windows and doors, you’ve run into this: the window schedule and the elevations don’t say the same thing. It doesn’t happen on every set, and it doesn’t happen on every sheet, but it happens often enough that trusting one document over the other out of habit will eventually get a wrong unit built.

This piece walks through why the two documents drift apart, a field-by-field way to catch the mismatches before they turn into a price, and a rule for deciding which document wins when they conflict.

Why the schedule and the elevations drift apart

The schedule and the elevations usually come out of the same office, sometimes even the same drafter, but they don’t get revised in the same pass. That’s where most of the mismatches start.

Revisions land on one sheet, not both. An architect changes a window arrangement on the elevation to fix a proportion, and the schedule row that used to describe it doesn’t get touched until two revisions later, if it ever does. It works in reverse too: someone resizes an opening on the schedule to hit an energy code minimum, and the elevation keeps showing the old proportions. Each revision is another chance for the two to split.

Then there’s the word “typ.” on a schedule line, which really means “go count them yourself.” If the elevation picked up one more instance of that unit in a later revision, the schedule quantity is wrong, and nothing on the page tells you so.

Mirrored floor plans cause a specific kind of trouble. Sometimes the schedule uses one mark to cover both a unit and its mirror image; sometimes it lists two marks where the elevations only bother to show one. Handing especially tends to survive in the drawing and disappear from the schedule.

And there are the late changes. Three days before the set goes out, someone swaps a casement for an awning window to clear space over a countertop, or bumps a door up two inches. Whatever document was open on screen at that moment gets updated. The other one ships as it was.

Two documents built to answer different questions, revised by different people at different points in the schedule, will drift apart. That’s normal, and catching where they’ve drifted, before it becomes a purchase order, is the estimator’s job.

How to detect the mismatches: a field-by-field checklist

Reconciliation works better as a specific pass, one field at a time, than as a vague “check for problems.” For every mark on the schedule, walk through these:

• Mark. Every mark on the schedule should show up somewhere on the elevations, and every tagged opening on the elevations should show up on the schedule. Anything orphaned on either side is worth a second look before you count it.
• Quantity. Actually count each mark across every elevation, mirrored ones included, and check that against the schedule’s stated quantity. Marks labeled “typ.” deserve extra suspicion here, since that’s exactly where quantities go stale.
• Size. Compare the schedule’s width and height to the dimensioned elevation. No dimension on the elevation? Check the floor plan opening instead. If an opening has no dimension anywhere on the set, don’t guess at it. Send the question to the architect.
• Operation. The dashed sight lines on the elevation should match the operation column on the schedule. Drawing a fixed unit with vent lines (or the reverse) is one of the costlier things to get wrong, because it changes hardware, price, and sometimes code compliance all at once.
• Handing. Check handing on casements, doors, and sliders against the elevation, and if the plan is mirrored, check it against the mirrored elevation specifically, not the base one you’d naturally look at first.
• Glazing. Tempered, obscure, insulated makeup, spandrel. The schedule usually carries this, but general notes or the elevations themselves sometimes override it near hazardous locations, so it’s worth checking both.
• Egress. Bedrooms and other required exits have minimum clear-opening rules. A scheduled size that looks tight for a sleeping room opening is worth flagging even when the schedule and elevation happen to agree, because they can both be wrong the same way.

Write every discrepancy down as you find it, with sheet references on both sides. A mismatch you can’t point to on paper is one you’ll end up re-finding next week.

Resolving conflicts before the shop floor

Once you’ve got the list, you need a rule for which document wins. A workable order of precedence for fenestration looks something like this:

1. The schedule wins on attributes. Size, glazing makeup, finish, hardware: that’s what the document was written to specify, so when it disagrees with a rough elevation on these, trust the schedule.
2. The elevations win on quantity, location, and configuration. How many units, where they sit, how they’re grouped or mulled together: that’s what the drawing of the actual building shows, and a table can’t out-argue a drawing of the wall it’s describing.
3. The floor plan settles disputes about whether an opening exists at all, or where exactly the rough opening sits.

That order handles the routine cases. It doesn’t give you license to resolve the expensive ones on your own. Send an RFI instead whenever the conflict touches operation, handing, or egress; when the two documents disagree by more than a nominal amount; when either answer meaningfully changes the price; or when the project’s own general notes spell out a different precedence order than the one above, since the contract documents always override any default rule like this one.

An RFI costs you a day to answer. Guessing wrong costs you a remake, and a remake costs a lot more than a day.

What a remake actually costs

It’s tempting to skip all of this when the bid is due Friday. But think about what one wrong unit actually costs once it’s already built: the material and labor for the original piece, the same again for the replacement, freight in both directions, whatever crane or crew time sits idle at the site waiting on the new unit, and the slot in your own shop’s schedule you have to bump something else to make room for. Catch the mismatch at takeoff and the fix is a line in an RFI. Miss it, and you find out at installation, when it’s suddenly the most expensive window on the job, with your company’s name on the delivery ticket that has to make a return trip.