Why bathroom costs vary so much
Bathrooms are small, but they concentrate several expensive building systems into one room. Labour access can be awkward, waterproofing has little tolerance for errors, and the cost difference between basic and premium fixtures is enormous. Existing conditions matter too: an easy surface replacement is different from repairing rot, replacing old plumbing or correcting an uneven floor.
Use cost buckets
| Budget bucket | What it may include | Questions to ask |
|---|---|---|
| Demolition & disposal | Protection, removal, bins or haul-away | Is hazardous-material testing needed for an older building? |
| Plumbing | Rough-in changes, valves, drains, fixture connections | Are fixture locations changing? |
| Electrical | Circuits, receptacles, lighting, controls, floor heat | What does local code require? |
| Moisture control | Ventilation, substrate, waterproofing membranes | Which system and warranty requirements apply? |
| Surfaces | Tile, grout, flooring, paint, wall panels | What waste factor and preparation are included? |
| Fixtures & cabinetry | Toilet, shower/tub, vanity, faucets, storage | Who orders and receives items? |
| Labour & management | Carpentry, tile, finishing, coordination | Are permits and inspections included? |
Budget for unknowns
Renovations reveal concealed conditions. A contingency is not “extra money to spend”; it is a reserve for conditions that could not reasonably be confirmed before demolition. The appropriate amount depends on the age of the building, how much is being opened, and how certain the existing conditions are.
Spend where replacement is difficult
Waterproofing, plumbing rough-ins, ventilation routing, electrical work and substrate preparation are expensive to revisit after finishes are complete. Decorative mirrors, towel bars, paint colours and some light fixtures are comparatively easy to change later. If the budget is tight, prioritize the work that will be buried behind the finished room.
Compare quotes on scope, not total alone
A lower quote can simply exclude work that another contractor included. Compare line items, allowances, product responsibility, permits, disposal, protection, warranty, payment schedule and how unforeseen conditions are handled.