How Much Contingency Margin Should You Hold Back on a Bathroom Remodel Bid?

Most bathroom remodel bids carry a contingency of 10% to 15% of the total price. That range exists because 'contingency' isn't insurance against everything going wrong — it's a reserve for the specific unknowns that show up once demo starts: a subfloor that turns out softer than the walk-through suggested, a shutoff valve that won't close, a vent stack that has to move six inches to clear a new vanity. On a job where the scope was set by eye rather than by opening anything up, 10% is the floor, not the target.

Fifteen percent is the number experienced remodelers reach for by default on a full bathroom gut — tile, vanity, tub or shower, plumbing rough-in. It covers one or two moderate surprises without forcing a change order conversation for every one of them. Contractors who bid tile work specifically should treat this contingency as separate from the material waste allowance already built into the tile takeoff — the /bathroom-tile-calculator handles the per-room overage on tile and grout, but that percentage covers cut waste, not a rotted joist.

Three conditions reliably justify moving contingency above the standard range. First, home age: houses built before 1978 fall under the EPA's Renovation, Repair and Painting Rule, which means lead paint testing and containment procedures if the existing finishes are disturbed — a cost and schedule variable that isn't visible during a normal walk-through. Second, unopened construction: if nobody has pulled tile or drywall off the walls in this bathroom before, the bid is priced against an assumption, not an inspection, and that gap is exactly what contingency exists to cover. Third, scope changes mid-project — moving a drain line, relocating a window, changing a tub to a curbless shower — each of which touches framing, waterproofing, and slope in ways that ripple past the original estimate.

When two or three of those conditions stack — a 1960s house, a shower being converted to curbless, walls that haven't been opened since the original build — 30% stops being padding and starts being realistic. That's also the range where it's worth having a documented walk-through with photos before the bid goes out, so the client can see why the number is what it is rather than assuming it's a hedge.

Skipping contingency doesn't make the risk disappear — it just moves who absorbs it. When a hidden problem surfaces on a bid with no reserve, the contractor has two options: eat the cost and finish the job at a loss, or issue a change order the homeowner wasn't prepared for. Both outcomes damage the relationship. The first erodes margin on every job that follows because underpricing becomes the habit. The second turns a routine subfloor repair into an adversarial conversation, because the client reads an unplanned charge as either poor estimating or padding after the fact — neither of which is true, but the bid didn't make room to prove it.

The pattern shows up most often on jobs bid from a single visual walk-through with no allowance line at all. The estimator prices exactly what's visible, the number looks competitive, and the client accepts it — right up until the tile comes off the wall and the real condition of the wall assembly becomes the topic of a phone call nobody wanted to make midway through the job.

Contingency works best as its own line item, not folded silently into the labor or material rows. On a $12,000 bathroom remodel bid, a 5% reserve is $600, a 15% reserve is $1,800, a 20% reserve is $2,400, and a 30% reserve is $3,600 — showing the client that range, tied to the specific conditions that drove the percentage, turns contingency from a suspicious markup into a documented risk allowance they can see the logic behind.

Keep this reserve mentally separate from material waste allowance. Tile, thinset, and grout overage — typically around 10% by Tile Council of North America guidance — covers cut waste, breakage, and pattern loss, and belongs in the takeoff, not the contingency line. Run that math through the /tile-estimator before finalizing quantities so the material budget is accurate on its own, then layer the contingency percentage on top of the full project total for the unknowns that live in the walls and floor, not in the tile boxes.