MEP plan coordination

What needs to line up

The mechanical, electrical, and plumbing plans need to be coordinated with each other and with the architectural plan before you submit. On a small DADU this is often informal — the designer marks up routes and the trades confirm during the bid.

For permit submittal, PP&D wants to see at minimum:

• Electrical: panel schedule, load calculation, branch-circuit layout, EV-readiness if applicable
• Plumbing: isometric of waste/vent and water supply, fixture schedule, water-heater type
• Mechanical: heat pump sizing per Manual J, ducting or mini-split layout, ventilation (Oregon requires whole-house mechanical ventilation)

Where the conflicts show up

• Bathroom vent vs. structural framing. The vent stack has to penetrate the roof; framing has to allow it.
• Heat pump line set route. The condensing unit is outside; the line set has to reach the air handler. Don't bury that requirement.
• Panel location. Has to satisfy NEC working clearances and stay accessible to PGE for meter reading.

When to bring in the trades

For pre-approved plan sets, MEP is already worked out — you just confirm which equipment options fit the budget. For custom designs, plan a 30-60 minute meeting with each trade before submittal. Most subs will do this for free if they get to bid the install.