Confirm the IPC edition and amendments the jurisdiction enforces, then trace fixtures, water supply, drainage and vent piping, and risers through the plumbing plans, isometrics, schedules, and architectural plans. AI can flag conflicts; the plumbing engineer confirms sizing and compliance.
What does the IPC cover?
ICC describes the International Plumbing Code as establishing minimum requirements for plumbing systems using prescriptive and performance-related provisions.
ICC publishes the I-Codes as model codes in editions. ICC’s 2024 I-Codes collection includes the IPC, and the ICC IPC overview describes how it is adopted; both were checked on October 1, 2026. States and cities adopt a specific edition, often with amendments, and many still enforce an earlier one. Record the edition and amendments the authority having jurisdiction actually enforces; the newest published edition does not establish local adoption.
Some states adopt the Uniform Plumbing Code instead, and Oregon adopts its own plumbing specialty code. Record which plumbing code the authority enforces before checking fixture counts or piping requirements. The plumbing fixture count explainer covers how fixture counts are reviewed.
Bring plumbing, architecture, and structure together
Collect plumbing floor plans, riser diagrams and isometrics, fixture schedules, water heater and equipment schedules, site utility connections, architectural plans and enlarged toilet room plans, accessibility details, and structural framing where piping penetrates. Add the plumbing specifications.
Fixture locations change often during design. Check that the plumbing fixture schedule and plans match the current architectural layouts.
Trace fixtures and piping through the set
| Review question | Sources to compare | Decision to record |
|---|---|---|
| Fixtures | Architectural plans, plumbing plans, fixture schedule | Identify fixtures added, moved, or removed in one document only. |
| Fixture count basis | Code summary, occupant load, fixture schedule | Ask the designer to confirm the basis where occupant loads changed. |
| Drainage and venting | Plans, isometrics, riser diagrams | Match pipe routes and connections between plans and diagrams. |
| Water supply and heaters | Riser diagrams, equipment schedule, site utility plans | Trace the supply from service to fixtures and heaters. |
| Structural penetrations | Plumbing routes, structural framing, slab details | Locate pipes crossing beams, slabs, or shear walls without a detail. |
| Accessible fixtures | Enlarged plans, accessibility details, fixture schedule | Reconcile accessible fixture types and locations across documents. |
Use the plumbing drawing checklist as the working log and the plumbing fixture specification guide for the fixture section.
Example: a lavatory moves without its piping
Hypothetical example. The enlarged toilet room plan moves a lavatory to the opposite wall, while the plumbing plan and isometric still show its waste and supply on the original wall.
The enlarged toilet room plan shows the lavatory on a different wall than the plumbing plan and isometric. Please confirm the fixture location and coordinate the piping.
The plumbing engineer updates the plan and isometric for the current layout. The conflict is a coordination question for the engineer.
Review plumbing code coordination with Groundbook
Upload the current drawings and specifications to Groundbook, and state the code edition, amendments, and review scope in your instructions. Add the applicable IPC from a copy you are licensed to use, where the license permits uploading it, and add the jurisdiction’s published amendments. See how Groundbook works with local and licensed codes.
Compare plumbing plans, isometrics, riser diagrams, and fixture schedules with current architectural and enlarged plans, the code summary, and structural framing. Flag fixtures and piping that disagree. Use the supplied IPC edition and amendments where applicable and cite both sources.
Groundbook links each potential finding to the sheets involved. Verify the fixture and revision before sending a question to the engineer.
Document review does not size pipes, calculate fixture units, or approve a plumbing design. Those remain with the plumbing engineer and the authority having jurisdiction.