What each one actually means
Both are legitimate ways to price construction work. The difference is who carries the risk if the job takes longer or costs more than expected.
- Fixed-bid (lump sum)— the contractor quotes one number for a defined scope. If it takes longer or materials cost more than they figured, that's on them. The price you sign is the price you pay, unless you change the scope.
- Time-and-materials (T&M)— you pay for actual labor hours plus the cost of materials, usually with a markup. The final number isn't known until the work is done. The risk sits with you.
Fixed-bid moves the risk to the builder. T&M keeps it with the homeowner. That's the whole story — everything else is detail.
Where each one makes sense
Neither is a scam. A good contractor uses the right one for the situation:
| Pricing | Best for | Who carries the risk |
|---|---|---|
| Fixed-bid | Defined scope — kitchens, baths, additions, decks | The contractor |
| Time-and-materials | Unknown conditions — demo, repairs, “open it up and see” | The homeowner |
| T&M with a cap | Uncertain scope you still want a ceiling on | Shared — capped at the not-to-exceed |
Most full remodels should be fixed-bid. Genuinely unknown work — opening a wall in a 1950s house, chasing a leak — is honestly quoted T&M, ideally with a cap.
The catch with each
A fixed bid is only as good as the scope behind it. If the scope is vague, the contractor either padded the number to cover themselves, or they'll come back with change orders the moment anything is unclear. A real fixed bid comes with a line-item scope and an allowances sheet so you can see exactly what's in and what's out.
T&M's catch is obvious: open-ended. Without a cap and without itemized timesheets, you're trusting that every logged hour was necessary. T&M is fine when conditions are truly unknown — but ask for a not-to-exceed number and receipts.
What a real fixed bid includes
If a contractor hands you a one-line number with no breakdown, that's not a fixed bid — it's a guess waiting to creep. A real one has:
- A line-item scope of work— what's being demoed, built, and finished, room by room.
- An allowances sheet — set dollar amounts for finishes you pick later (tile, cabinets, fixtures), so the budget is clear and you stay in control.
- A payment schedule — draws tied to milestones, never paid ahead of completed work.
- A change-order clause — any scope change gets priced and approved in writing before work proceeds.
So which should you ask for?
Fixed-bid for any project with a knowable scope — which is most remodels. You get a number you can budget around and the contractor owns the overruns. This is the right default for homeowners.
T&M with a capwhen there's a real unknown — old wiring, suspected water damage, a foundation question. The cap gives you a worst case while still paying only for what the work actually takes.
Pure, uncapped T&Monly for small, short, genuinely open-ended fixes — and only with itemized timesheets. For a whole remodel, uncapped T&M is where budgets quietly double.
The real tell
However a contractor prices it, the protection is in the paperwork. A clear scope, an allowances sheet, a milestone payment schedule, and a written change-order process — that's what keeps the final invoice matching the bid. Anyone who won't put the scope in writing is the risk, not the pricing model. We quote fixed-bid by default, and we'll tell you straight when a piece of your project genuinely belongs on T&M — with a cap.