- Skipping a 10–20% contingency for hidden damage.
- Moving plumbing without need ($2,500–$5,000 per drain).
- Poor ventilation leading to mold.
- Cutting corners on waterproofing.
- Hiring on price alone without comparing scope.
Get up to 3 free estimates from licensed local contractors →
Related
Frequently asked questions
What is the biggest bathroom remodel mistake?
Underbudgeting — always reserve a contingency for surprises behind walls and floors.
Sources: national bathroom remodel figures (range $2,500–$30,000, ~$12,140 average, $70–$250/sq ft, small/mid/primary ranges, drain-move cost) come from the BathEstimates 2026 cost guide. All other ranges (tub-to-shower, walk-in shower, bathtub replacement, city adjustments) are BathEstimates editorial estimates based on typical scope, materials and labor — not survey data. Always compare written quotes from licensed local contractors.