Plan the fixture layout and verify local plumbing codes
Shut off the main water supply
Mark the locations for toilet, sink, shower, and tub drains and supplies
Install the drain-waste-vent system
Set the toilet flange at the correct finished floor height
Run hot and cold water supply lines to each fixture
Install shutoff valves for sink, toilet, and other fixtures
Connect the sink drain, trap, and vent
Connect the toilet to the flange and water supply
Install shower or tub drain, trap, and vent
Pressure test the water supply lines
Test drain flow and check for leaks
Secure and insulate exposed pipes as needed
Close walls and flooring after inspections
Install fixtures and connect final supply and drain fittings
Turn water back on and perform final leak checks