Bathroom plumbing is where small decisions get expensive — moving a toilet 6 inches can add $1,000+ to a remodel, while keeping fixtures in place keeps budgets sane. Rough-in plumbing for a new bathroom runs $1,500–$7,500+ depending on layout and how far the new lines must travel. This section covers rough-in costs, remodel budgeting, fixture installation, and the layout choices that control the final bill.
Fixture location is the budget lever
Drain lines need slope (1/4 inch per foot), which is why moving fixtures means opening floors and rerouting. Design around existing drain locations and the plumbing budget drops dramatically — our remodel guide shows the trade-offs.
Venting is not optional
Every fixture needs venting to drain properly. DIY bathroom plumbing fails inspection on venting more than anything else — our guides explain wet venting rules in plain English.