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Permit Drawings vs Construction Drawings — What Your Ontario Project Actually Needs

June 2026 10 min read May Engineering Inc

Two Different Drawing Sets, Two Different Jobs

A common source of confusion — and cost — in Ontario is thinking a permit drawing set and a construction drawing set are the same document. They serve different purposes, satisfy different reviewers, and on a real project you almost always need both, often produced at different times.

The permit set is what you submit to the municipality. Its job is to prove the design complies with the Ontario Building Code (Part 3 or Part 9 depending on your building) — enough information for the building official to approve the work. The construction set ("IFC", issued for construction) is what builders price and build from — it carries the coordination, detailing, and tolerances needed on the job site.

The permit set proves code compliance to the municipality. The construction set builds the project. Confusing the two either delays your permit or breaks your field.

In the permit set

Site plan, floor plans, elevations, sections, electrical/mechanical schematics, SB-10/SB-12 energy compliance, limited structural notes.

In the construction set

Every dimension resolved, connection details, schedules, coordination between trades, tolerances, and structural shop-ready information.

What's Actually Inside an Ontario Permit Set

1

Site plan

Property lines, setbacks, footprint, zoning compliance, existing and proposed structures, driveway and parking.

2

Floor plans with dimensions

Room-by-room layout, window and door sizes, and wall/opening locations — fully dimensioned.

3

Elevations

Each exterior face drawn to scale — a required drawing too often left out on renovations.

4

Sections and details

Structural assemblies, foundation details, roof framing — enough to show the municipality how it will be built.

5

Code compliance narrative

The energy compliance form (typically SB-10 or SB-12 with reports), plus notes showing compliance with Part 3 or Part 9.

6

Structural notes / engineering

For engineered work, the permit set references the P.Eng.-sealed structural package required by the municipality.

The Trap: A Permit Set That Isn't Buildable

Here's the failure mode: a company produces a permit set, gets the stamp, and the homeowner thinks they're ready to build. Then the general contractor looks at the drawings, sees knots where the corners should be, vague structural notes, and no coordination between the electrical and the framing — and quotes a change order to "make the drawings buildable" or turns the job down.

A stamped permit is not a complete design. On renovation and addition work, the gap between "permit-approved" and "actually buildable" is where budget and schedule blow out. Budget for both sets.

May Engineering Inc: Both Sets, One Team

May Engineering Inc produces complete permit drawing sets and buildable construction drawing sets, plus the P.Eng.-sealed structural package that sits underneath both. Because one team does the architectural, structural, and coordination work together, the permit set you submit is the same intent the construction set executes — no translation gap, no surprise change orders.

Planning a renovation, addition, or new build in Ontario? Our permit drawing services scope what your municipality actually requires and build one set that gets stamped and another that gets built. Request a quote to start.

Planning a renovation or addition?

May Engineering Inc produces permit-ready and buildable construction drawing sets across Ontario, with P.Eng.-sealed structural support throughout.

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