Do I need a permit for a bathroom remodel?

A like-for-like fixture replacement (new tub, toilet, vanity in the same locations) usually doesn't need a permit. Anything that moves plumbing, opens walls beyond the existing tile area, changes electrical (new circuit, new fan), or adds a bathroom requires a permit. Permit costs range $150–$1,200 nationally. Permitted work passes inspection — which is the only thing standing between you and an insurance denial or buyer's-inspector finding during resale. The single most common DIY-mistake costing homeowners $$$ is unpermitted plumbing relocation that fails the next inspection and forces rip-out.