7 Common Permit Drawing Mistakes in Ontario — And How to Avoid Rejection

Every Review Cycle Is Weeks You Don't Have

Municipal building departments in Ontario review your application on a fixed clock — and when your drawings are missing something, they issue a deficiency notice, not a fix. You address it, resubmit, and the clock starts again. A single preventable mistake routinely adds 4 to 8 weeks to a project that was already going to take months.

The frustrating part: most of the reasons permit drawings are rejected are known and avoidable. These are the seven we see most often across Ontario municipalities.

“A building permit is not a reward for effort — it's approval of a complete, code-compliant document set. Incomplete isn't almost-approved; it's not started.”

The Seven Mistakes (in Order of How Often We See Them)

No elevations (or only two of them)

One of the most common rejections. Municipalities want all four exterior elevations drawn to scale — including on renovations, where a missing rear elevation is a guaranteed deficiency.

Incomplete or missing energy compliance

Ontario requires an SB-12 (or SB-10) energy compliance form with the specific envelope and system inputs for your project. A generic form, or one with blank cells, won't clear review.

Structural work with no P.Eng. package

Removing a wall, an opening in a floor, foundation work — municipalities will hold the permit until the P.Eng.-sealed structural drawings arrive. This is the #1 cause of multi-month stalls.

Dimensions that don't add up

A plan where the interior dimensions don't reconcile to the overall footprint, or that contradicts the elevations, reads instantly as an unbuildable sketch — not a submittable drawing set.

Undimensioned or decorative drawings

Plans without fenestration schedules, wall sections, or junction details. The reviewer can't tell what you're proposing to build, so they can't approve it.

Wrong code part or missing compliance path

Submitting a Part 9-style set for what's actually a Part 3 building, or no clear narrative on how the design meets the applicable Building Code. The reviewer has to guess your intent.

No zoning/clearance confirmation

Setbacks, height, or parking drawn outside permitted zoning. Checked against the permit application, this can stop the file before drawings are even reviewed for code.

The Cost of Resubmission vs. the Cost of Doing It Right

Here's the economics that should decide it for you. One resubmission cycle on an Ontario permit costs you weeks of calendar time, frustration, and on commercial projects, holding costs on money you've already borrowed. Getting the drawing set right the first time costs the difference between a $6,000–$15,000 complete permit package and a $3,000 set missing half of what the municipality needs.

The complete set is the cheap option. Every missing drawing or missing stamp is a review cycle you pay for twice — once in the deficiency, once in the weeks of schedule it consumes.

May Engineering Inc: Complete the First Time

May Engineering Inc builds permit drawing sets to be complete the first time — the elevations, the SB-12 energy compliance, the zoning confirmation, and the P.Eng.-sealed structural package, coordinated by one team that knows what each municipality in Ontario actually asks for. We've drawn enough permits to know the difference between the set that sails through and the set that comes back a month later.

Not sure your current drawings will pass review? Send us your set for a review — we'll tell you exactly what's missing before you hand it to the municipality, not after.