This free interactive 3D model walks you through the plumbing systems of a 2-story residential/small-commercial building — the cold and hot water supply, the sanitary drainage (DWV) system, the vent stack, and every major fixture in between. Click any component to see what it does, how it's sized, and the code section it falls under. It's a visual learning tool for plumbing designers, apprentices, inspectors, and anyone studying how a building's water and waste systems actually connect.
The viewer covers the full path of water into, through, and out of the building:
• Water supply — service entrance, meter, main shutoff, pressure-reducing valve, water heater, and expansion tank. • Fixtures — kitchen sink, dishwasher, washing machine standpipe, water closets, lavatories, and a tub/shower. • DWV drainage — P-traps, cleanouts, the main soil/waste stack, the building drain, and the sewer lateral connection. • Venting — the vent stack roof penetration and an air admittance valve (AAV). • An animated water-flow marker traces the supply path (source → fixture) and the drain path (fixture → sewer) whenever you click a fixture.
Potable water enters through the service line, passes through the meter and main shutoff, and is often reduced to a safe working pressure by a PRV. From there, cold water branches directly to fixtures while a portion is heated by the water heater and distributed as a separate hot line. Each fixture drains through a trap (a water seal that blocks sewer gas) into a branch line, which ties into the main stack. The stack carries waste down to the building drain and out to the sewer or septic system, while continuing upward past the roofline as a vent stack — equalizing air pressure so trap seals aren't sucked dry by the flow of water below.
1. Drag to orbit the building, scroll to zoom, and pan to move around. 2. Use the FLOOR buttons to isolate floor 1 or floor 2 — grade-level equipment (water heater, meter, stack, sewer connection) is always shown. 3. Toggle Cold Supply, Hot Supply, Drain (DWV), and Vent (DWV) independently to isolate a system. 4. Click any fixture or component for its name, code reference, typical size/material, and function — and watch the glowing markers trace its supply and drain path.
DWV stands for Drain-Waste-Vent — the piping network that carries wastewater out of a building (drain/waste) while admitting air to prevent trap seals from siphoning and to let sewer gas escape safely through a vent stack above the roofline.
A P-trap retains a small amount of water that forms a seal blocking sewer gas from entering the building through the fixture drain. Fixtures like toilets have an integral trap built into the fixture body, so a separate P-trap fitting is not required.
A vent stack extends the drainage system through the roof to atmosphere. As wastewater flows down the stack it can create negative pressure that would otherwise siphon water out of nearby trap seals; the vent equalizes that pressure and lets drainage flow smoothly.
Cold water is distributed directly from the service entrance to fixtures, while a portion is routed through the water heater and distributed as a separate hot-water line so that fixtures needing hot water (sinks, showers, the dishwasher, the washing machine) can draw it on demand.
A cleanout is a capped access fitting installed at the base of a stack, at major direction changes, and along long horizontal drain runs. It lets a plumber insert a cable or camera to clear or inspect a blockage without cutting into the pipe.