The 7 MEP Plan-Check Comments I Wrote on Almost Every Set
From the reviewer's chair to founding CoreX — the seven comments I wrote on almost every plan set that crossed my desk, and how to keep them off yours.
- If the energy path isn't handed to the reviewer on the right form, matching the drawings, it can trigger a comment.
- Each contradiction can trigger a comment, and collectively they can signal the disciplines weren't coordinated, so the reviewer may look harder at everything.
- Run the checklist the day before you issue: the time the checks take depends on the set's size and complexity; a resubmittal can cost weeks.
Before founding CoreX, I worked on the other side of the table: reviewing MEP systems through third-party peer reviews, third-party plan reviews, and code-compliance evaluations — and contributing to many projects across my career. That combination is what taught me to read a set quickly, looking for the details most likely to send it back.
A reviewer usually knows within the first few minutes whether a set is going to be clean or painful. Not because they've checked every calculation yet — because the tells are everywhere. A missing schedule. A note that doesn't match a plan. An energy form that isn't there. Those tells can reveal issues that lead to additional review cycles and delays.
So let me give you the reviewer's view. These are the seven comments I found myself writing on almost every set that came across my desk — and, more usefully, how to keep them off yours.
Seven common MEP plan-check comments are: undocumented energy-code compliance, ventilation that doesn't trace to ASHRAE 62.1 or the adopted mechanical code, an electrical load calc that disagrees with the panel schedule, life-safety/floor-plan mismatches, plumbing fixture counts that don't match occupancy, generic details with no local amendments, and cross-discipline contradictions. Eliminate all seven and you give the reviewer fewer reasons to send the set back.
The seven at a glance — each one is expanded below:
| Comment | What the reviewer sees | Keep it off your set |
|---|---|---|
| 1. Energy-code path isn't documented | No COMcheck or Title 24 forms, or a COMcheck whose lighting power density doesn't match the lighting schedule | Finish the compliance package with the design, on the form the jurisdiction accepts, and cross-check every value against the schedules |
| 2. Ventilation rates don't trace to code | Outdoor-air CFM with no visible path back to ASHRAE 62.1 or the adopted mechanical code | Show the ventilation basis — a short table or referenced calculation from occupancy to CFM |
| 3. Load calc doesn't match the panel schedule | A service load calculation that can't be reconciled with the panel schedules | Reconcile the load calculation and the panel schedules as a pair before every issue |
| 4. Life-safety plan and floor plan disagree | Egress paths, exit signs or occupant loads that don't match the architectural | Coordinate life safety against the current architectural background |
| 5. Fixture counts don't match the occupancy | A plumbing fixture count that differs from what the code plan's occupant load requires | Pull the fixture count from the same occupant load the code plan uses |
| 6. Generic details, no local amendments | Manufacturer-standard details and national-code notes only | Check the local amendments and reflect them in the notes, details and energy path |
| 7. The set contradicts itself across disciplines | A unit with no feed, a pipe through a beam, a roof curb mechanical doesn't know about | Coordinate before you submit — a federated model or a disciplined manual overlay |
1. The energy-code path isn't documented
This is a common and often avoidable issue. The drawings are fine, the systems are sized, and then there's… nothing tying it to the energy code. No COMcheck. No Title 24 forms. Or there's a COMcheck, but the lighting power density on it doesn't match the lighting schedule three sheets over.
A reviewer isn't going to reverse-engineer your compliance. If the energy path isn't handed to them — the right form for the jurisdiction, matching the drawings — it can trigger a comment.
Keep it off your set: finalize the energy-compliance package with the design, not after. Confirm which document your jurisdiction actually accepts (COMcheck won't fly in California — that's Title 24), and cross-check every value on it against the schedules before you submit. COMcheck is the U.S. Department of Energy's free compliance tool; California's Title 24, Part 6 is administered by the CEC.
2. Ventilation rates don't trace back to the code
I'd see a mechanical schedule with outdoor-air CFM on it and no way to check where the number came from. ASHRAE 62.1 (the standard that sets minimum ventilation for acceptable indoor air quality), and the adopted mechanical code's ventilation table built on the same method (IMC Table 403.3.1.1 in IMC jurisdictions), give you a defined path — occupancy category, people component, area component. If your OA numbers don't visibly trace to that path, the reviewer either takes it on faith or writes the comment. Most write the comment.
Keep it off your set: show the ventilation basis. A short table or a referenced calculation that lets the reviewer follow the number from occupancy and area to intake CFM, with Ez and Ev where the method uses them, turns a question into a check-mark. The standard itself is published by ASHRAE.
3. The electrical load calc doesn't match the panel schedule
Classic. The service is sized to one number in the load calculation, and the panel schedules can't be traced to it. Or the calc uses demand factors the schedules don't reflect. When the two documents disagree, the reviewer can't tell which one is real — so both get flagged. I've flagged a load calc that sized a service the panel schedules didn't add up to — a five-minute reconcile on paper, a correction cycle if it ships.
Keep it off your set: reconcile the electrical load calculation and the panel schedules as a pair, every time, before issue. They're two views of the same system; they have to agree. The load-calculation rules are in Article 220 of the 2023 NEC (NFPA 70)— Article 120 in the 2026 edition.
4. The life-safety plan and the floor plan disagree
Egress path on the life-safety sheet doesn't match a wall on the architectural. An exit sign in a location the plan doesn't support. Occupant loads that don't line up with the fixture count, or a ventilation population that differs without explanation. Reviewers read life safety carefully because it's life safety — and inconsistencies here erode their confidence in the entire set.
Keep it off your set: coordinate the life-safety plan against the current architectural background, not last month's. When the reviewer sees life safety line up cleanly, they trust the rest of the drawings more.
5. Plumbing fixture counts don't match the occupancy
The plumbing sheets show a fixture count; the occupancy on the code plan implies a different one. Under the IPC/UPC, required fixtures are driven by occupant load and use group — so when those two don't agree, it can draw a comment, and sometimes a redesign.
Keep it off your set: pull the fixture count straight from the same occupant load the code plan uses. One source of truth, carried through.
6. The details are generic — no local amendments
A set full of manufacturer-standard details and national-code notes, with zero acknowledgment that the project is in a jurisdiction with its own amendments. Reviewers notice immediately when a set was clearly produced without opening their code. It reads as "this team doesn't know where they are."
Keep it off your set: check the local amendments and reflect them — in the code notes, the details, the energy path. It's a small effort that signals you did your homework, and it can head off a whole category of comments.
7. The set contradicts itself across disciplines
This is the coordination tell, and it's the one that tells a reviewer the most. Mechanical shows a unit where electrical shows nothing to feed it. Plumbing routes through a beam. A curb on the roof plan that mechanical doesn't know about. Each contradiction can trigger a comment — and collectively they can signal that the disciplines weren't coordinated, so the reviewer may look harder at everything.
Keep it off your set: coordinate before you submit, not after the city does it for you. A federated model or even a disciplined manual overlay can catch many of these. Building departments or authorities having jurisdiction (AHJs) may catch some of them, but permit review isn't a comprehensive coordination check; better that you find them first.
What This Looks Like in Practice
None of these seven are exotic. They're the boring, preventable stuff — and that's exactly why they matter. A set that eliminates all seven doesn't just avoid those comments; it changes how the reviewer reads the whole submission. They can spend their time verifying compliance instead of hunting for avoidable inconsistencies. If you want to see what that discipline looks like on the sheet itself, how to read MEP drawings walks through the same permit drawings and construction documents a reviewer works from.
That reviewer's checklist is baked into how we work at CoreX, carried through SD, DD, and CD rather than bolted on at the end. Before anything goes to a building department for review, we run an internal design review and code compliance review against this exact list — the same scrutiny I used to apply from the review chair.
The Checklist I'd Run Before Submitting
If I were reviewing my own set before it went in, these are the checks that can head off the seven comments above — the same seven, turned into items I'd verify myself before a reviewer has to raise them for me:
- Energy compliance documentation matches the drawings — the forms and the set agree.
- Ventilation basis traces to ASHRAE 62.1 or the adopted mechanical code — the outdoor-air numbers are shown, not implied.
- Panel schedules reconcile with the load calculations.
- Life-safety plans match the architectural life-safety sheet.
- Plumbing fixture counts match the occupant load used in the code analysis.
- Local amendments incorporated for the specific jurisdiction.
- Cross-discipline coordination complete — mechanical equipment shown on structural, power on electrical, and so on.
Much of it isn't hard engineering; it's the discipline of checking — which is exactly what a reviewer is about to do for you. Run it the day before you issue, not the day you're rushing to meet a deadline — the time the checks take depends on the set's size and complexity; a resubmittal can cost weeks.
Related: Why MEP Sets Bounce at Plan Check · What Clients Get Wrong Before a Project · MEP Coordination Best Practices
Common Questions
Seven common ones are an undocumented energy-code path, ventilation rates that don't trace back to ASHRAE 62.1 or the adopted mechanical code, an electrical load calculation that disagrees with the panel schedule, a life-safety plan that doesn't match the floor plan, plumbing fixture counts that don't match the occupancy, generic details with no local amendments, and a set that contradicts itself across disciplines. Eliminating all seven changes how a reviewer reads the whole submission and can help a set move through review faster.
Cross-discipline contradictions — a mechanical unit with nothing feeding it electrically, plumbing routed through a beam, a roof curb mechanical doesn't know about — are the coordination tell reviewers notice fastest. Each contradiction can draw its own comment, and together they can signal the disciplines weren't coordinated before submission, so the reviewer may scrutinize everything else in the set more closely.
Finalize the energy-compliance package with the design rather than after, show the ventilation basis so outdoor-air numbers trace to ASHRAE 62.1 or the adopted mechanical code, reconcile the electrical load calculation against the panel schedules before issue, coordinate the life-safety plan against the current architectural background, pull plumbing fixture counts from the same occupant load used on the code plan, reflect local code amendments in the details and notes, and coordinate across all three disciplines before you submit rather than letting the city find the conflicts.
The Authority Having Jurisdiction — the organization, office, or individual responsible for enforcing the adopted codes or approving the work for a given project location. On a given project, that might be a city building department, a county, or in some cases a state fire marshal's office — and one project can have more than one AHJ (building, fire, electrical).
It varies widely by jurisdiction and workload; ask the AHJ about current correction-review queues, procedures, and any expedited options — and resolve the common comment causes before the first submission to reduce the chance of needing a second cycle (a resubmittal). A set that clears in one round generally moves faster than one that needs two or three.
An internal quality check run before a set is submitted — confirming coordination across disciplines, that code and energy documentation match the drawings, and that calculations and schedules reconcile — the kind of scrutiny a plan examiner applies, done earlier. It's the same discipline described in the checklist above, run before the reviewing authority ever sees the set.
No. It can reduce avoidable coordination comments, but the reviewing authority makes the final call on approval. It can also help make reviewer discussions clearer and responses easier to substantiate.
A plan-check comment comes from the reviewing authority during permit review, before construction; an RFI (Request for Information) is typically raised during construction when the field needs a clarification. Both exist to resolve open questions, but a comment can usually be prevented with a more thorough design review; an RFI often can't.
Senior electrical designer with 6+ years in U.S. MEP design, contributor to 900+ projects, and an experienced third-party peer and plan reviewer.
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