How to Quote a Job With Unknown Conditions
When conditions are hidden — under a slab, behind a wall, inside a sofa, beneath a vapor barrier — quote the visible scope firmly and price the unknown as a stated unit rate rather than a guess: an as-found rate per joist, per pier, per foot, or per hour, billed only after photo approval. Use allowances for items the customer will still be choosing, exclusions for what you refuse to absorb, and a paid site visit or exploratory opening when the range is too wide to quote at all.
Never bury an unknown inside a firm price
The instinct is to pad the number — add a cushion and hope it covers whatever’s under there. But padding loses you the jobs where nothing was wrong, and it still doesn’t cover you on the ones where everything was.
The better move is to quote the unknown as a rate instead.
The four tools
- As-found unit rate — “rotten joist repair, $X each, billed with photo approval”
- Allowance — a stated budget for something the customer hasn’t chosen yet
- Exclusion — a numbered list of what isn’t in the price, ever
- Paid investigation — a site visit or exploratory opening when the range is too wide
Write the rate before you need it
An as-found rate agreed at signing is just arithmetic. The same number introduced mid-job, with a hole already open, is a negotiation you’re conducting from the weaker position.
Print it on the estimate even when you expect not to use it.
Photo, price, approval — in that order
When you find something:
- Photograph it where the customer can actually understand what they’re looking at
- Send the number from the rate already agreed
- Get a written yes — a text is fine
- Then do the work
Reversing any two of those steps is how change orders turn into disputes.
Exclusions are specific or they’re nothing
“Unforeseen conditions not included” doesn’t persuade anyone. “Not included: drywall repair, painting, plumbing relocation, landscape restoration, structural work beyond the scope above” is a list a customer actually reads, remembers, and doesn’t argue with later.
Build yours from your last five difficult jobs — that’s about the most accurate guide you’ll find.
Charge for looking
Some jobs genuinely can’t be quoted from the outside. A paid site visit or exploratory opening produces real information, filters out people just collecting free guesses, and gets credited against the work when they proceed.
Refusing to guess is a mark of experience, and customers read it that way far more often than contractors expect.
Frequently asked questions
What's the difference between an as-found rate and an allowance?
An as-found rate prices work you may or may not have to do — rot behind siding, deeper piers than expected. An allowance prices something you definitely will do but whose cost the customer hasn't chosen yet, like a grill or a light fixture. Both convert an unknown into arithmetic instead of a fight.
Why require photo approval on change orders?
Because the customer usually can't inspect the condition themselves — it's under the house, behind the wall, or in a hole. A photo and a number sent by text, approved in writing before you continue, is the whole difference between a change order and an accusation.
Should I charge for an exploratory opening?
Yes, when the range is genuinely too wide to quote — cutting an inspection opening or pulling a section of siding is real work that produces real information. A paid investigation is far more honest than a padded guess or an optimistic one you'll regret.
How wide should my exclusions be?
Wide enough to name everything you refuse to absorb, specific enough to be credible. Vague exclusions read as evasive; a numbered list of five concrete items reads as professional and is what a customer actually remembers.