Confirm which OPSC edition the permit uses, since the 2026 edition took effect October 1, 2026, then trace fixtures, water supply, drainage and venting, water heating, and backflow protection through the plumbing plans, risers, schedules, and the architectural plans. AI can flag conflicts; the plumbing designer and the plumbing inspector decide compliance.
What does the OPSC cover?
The Building Codes Division describes the Oregon Plumbing Specialty Code as governing the installation, alteration, repair, relocation, and replacement of plumbing systems in commercial and residential buildings.
The Oregon Building Codes Division states that the 2026 OPSC is based on the 2024 Uniform Plumbing Code and took effect October 1, 2026. Its page did not state a phase-in or mandatory date when read. The previous OPSC took effect October 1, 2023. Checked October 15, 2026. Interim amendments and errata are posted on the same pages; confirm which edition the permit was applied for under.
Model code checks are in the UPC guide; projects outside Oregon may use the IPC instead. Fixture counts are explained in the fixture count guide.
Gather the plumbing drawings and fixture information
Collect the plumbing floor plans, isometrics or risers for water, waste, and vent, the fixture and equipment schedules, the water heater and backflow details, the architectural plans and occupant load, the site utility plan for the building service connections, and the plumbing specifications.
Note which code the plumbing general notes cite. Sheets reused from another state may still cite the IPC.
Trace OPSC items through the set
| Review question | Sources to compare | Decision to record |
|---|---|---|
| Edition and model code | Plumbing general notes, code analysis | Confirm the OPSC edition is cited rather than the IPC or an earlier OPSC. |
| Fixtures | Fixture schedule, architectural plans, occupant load | Match fixture counts and locations between plumbing and architecture. |
| Water supply | Riser diagrams, plans, equipment schedule | Check every fixture and appliance is served on the risers and plans. |
| Drainage and venting | Waste and vent risers, plans, sections | Find fixtures drawn without a drain or vent connection. |
| Water heating | Water heater schedule, details, mechanical and gas plans | Match water heater fuel, venting, and relief discharge across sheets. |
| Backflow and connections | Backflow details, site utility plan, plans | Confirm backflow devices and service connections are located consistently. |
The plumbing drawing checklist gives a working log, and fixtures are compared with the specifications in the plumbing fixture guide.
Example: a sheet still citing the IPC
Hypothetical example. A tenant improvement in Portland reuses plumbing sheets from a project in another state. The general notes cite the IPC, and the riser diagram sizes the waste lines with a note that refers to that code, while the code analysis cites the OPSC.
The plumbing general notes and riser diagram cite the IPC, while the code analysis cites the Oregon Plumbing Specialty Code. Confirm the governing code and update the plumbing notes and sizing references.
The plumbing designer revises the notes and confirms sizing under the OPSC. The plumbing inspector decides compliance.
Review Oregon plumbing drawings with Groundbook
Upload the current drawings and specifications to Groundbook, and state the edition, amendments, and review scope in your instructions. Add the Oregon Plumbing Specialty Code edition the project uses from a copy you are licensed to use, where the license permits uploading it, and the jurisdiction’s published amendments. See how Groundbook works with local and licensed codes.
Compare the plumbing plans, risers, fixture and equipment schedules, water heater and backflow details, architectural plans, site utility plan, and plumbing specifications. Flag IPC or outdated OPSC citations, fixtures that differ between plumbing and architecture, and fixtures or appliances without supply, drain, or vent. Use the supplied OPSC and cite both sources.
Groundbook links each potential finding to the sheets involved.
Document review does not size piping or approve the plumbing system. Those remain with the plumbing designer and the plumbing inspector.