What Every Electrical Contractor Needs to Know About Permit Drawings

Matthew Lohens
Jun 9
3 min read

If you've ever had a permit package sent back by the AHJ, you know the pain: the job is scheduled, the materials are on order, and now you're stuck waiting on corrections that could've been caught before you submitted.

Most rejections come down to the same few issues. Here's what I see repeatedly as a PE reviewing these packages — and what contractors can do to avoid the back-and-forth.

What the AHJ Actually Wants to See

Plan checkers aren't trying to make your life difficult. They're checking that the drawings show the work is safe and code-compliant. At minimum, a permit drawing package for most electrical jobs needs:

A site or floor plan showing where the equipment is located
A one-line diagram (riser diagram) showing the electrical system layout
Load calculations demonstrating the panel or service can handle the new load
Equipment specs — panel schedule, breaker ratings, wire sizes
PE stamp, if required by the AHJ or jurisdiction

The last one is where contractors often get caught off guard.

When a PE Stamp Is Required

Not every job needs a stamped drawing, but more do than most contractors expect. Requirements vary by AHJ, but you'll typically need PE-stamped electrical drawings for:

Panel upgrades and service changes — most jurisdictions require an engineer of record for service upgrades above a certain amperage (100A to 200A is common)
EV charger installations — especially commercial, multi-unit residential, or high-amperage Level 2/DCFC installs
Generator and ATS installations — almost universally require stamped drawings, load analysis, and interconnection details
Commercial tenant improvements — if electrical work is part of a TI, the AHJ almost always requires PE drawings
Any job where the AHJ asks for it — some plan checkers will flag a residential job if the load calc looks tight or the scope is unusual

When in doubt, call the building department before you submit. Five minutes on the phone saves weeks of corrections.

Why DIY Drawings Get Rejected

I see this constantly. A contractor puts together a permit package — usually a sketch, a panel schedule, and maybe a load calc pulled from a template — and the AHJ sends it back. Common rejection reasons:

Incomplete load calculations. A load calc that just adds up circuit breaker ratings isn't a load calc. The AHJ wants to see a proper demand calculation per NEC Article 220, showing the service is adequately sized for the connected load.

Missing one-line diagram. A floor plan alone isn't enough for most jurisdictions. They want to see the system topology: where the service entrance is, how it feeds the panel, what's downstream.

Wrong equipment specifications. Showing a 200A panel on a drawing when the equipment installed is something different — or not specifying the equipment at all — will get flagged.

No PE stamp when required. If the AHJ requires engineer of record drawings, they'll reject the package outright regardless of how complete it looks otherwise.

What Good PE-Stamped Drawings Include

When you submit PE-stamped drawings from MHL Consulting, here's what the package includes:

Site or floor plan with equipment locations
One-line diagram with equipment ratings and wire sizes
NEC-compliant load calculations (per Article 220)
Panel schedule showing existing and new loads
Equipment specifications and installation notes
PE signature and stamp, licensed in your state

The drawings are prepared to AHJ submittal standards, which means fewer corrections and faster approvals.

How to Work With a PE Efficiently

Contractors who get their permit drawings back fast do a few things consistently:

Send complete field info upfront. The more I have to guess about existing conditions, the longer it takes to produce accurate drawings. Send the existing panel schedule, the equipment specs for what's being installed, and a rough site sketch or photos.

Know your AHJ's requirements before you call. Some AHJs have specific drawing standards — title blocks, scale requirements, sheet sizes. If you already know what the plan checker wants, tell me when you submit. It speeds up the process significantly.

Don't wait until the last minute. PE drawings typically take 1–3 business days for standard jobs. If you have a hard permit deadline, give yourself buffer.

Ask about corrections before resubmitting. If the AHJ red-lines your drawings, send me the correction letter. I'll revise and re-stamp. Most corrections are straightforward once you know what the plan checker is looking for.

Plan Check Rescue: When You're Already Stuck

If your package has already been rejected and you need a PE to review the correction letter and provide compliant drawings, that's a service I offer directly — plan check PE review. Send me the AHJ's comments and the existing drawings and I'll tell you exactly what needs to change.