Quick note before we start

Inspection requirements can vary slightly by municipality and by project type (custom home vs addition vs renovation vs detached garage). The list below covers the most common mandatory inspections for a new Part 9 home in Ontario, plus the “usual extras” that show up depending on your design.

Why construction inspections in Ontario matter (beyond “because the City says so”)

It’s easy to think inspections are just bureaucracy. But the real purpose is simple: they protect you from hidden mistakes that become expensive nightmares later. A footing inspected before concrete is poured is cheap to correct. A footing found to be wrong after the house is framed? That’s the kind of discovery that causes grown adults to stare at the ground quietly.

Inspections also provide a paper trail that your home was built to the approved permit drawings and code. That matters for insurance, resale, and peace of mind. And if you’re doing high-performance building (ICF, radiant, advanced envelopes), inspections are often where good planning pays off.

If you’re still early in the process and want the “from zero to permit-approved” roadmap, read How to Get a Building Permit in Ontario. Inspections are the “after” part of that permit story.

Who books inspections in Ontario?

In most builds, the builder (or the person named as the permit holder) books inspections with the municipal building department. Some trades book their own specialty inspections depending on municipality and scope, but as a homeowner you should assume: if nobody books it, it doesn’t happen.

The typical mandatory inspection stages for a new home

Every municipality has its own inspection list, but for a standard new home, you’ll almost always see inspections that follow the build sequence. Below is a practical “what it is / what they look for / common problems” guide.

1) Site / setbacks / lot grading considerations (project-dependent)

Some jurisdictions confirm building location, setbacks, and site-related requirements early. This isn’t always called an “inspection” in the way homeowners imagine, but it can be a checkpoint that prevents a giant problem later (like building in the wrong place).

2) Footing / excavation inspection (before concrete)

This is the big one. The inspector checks that your footing excavation matches the plan: width, depth, soil bearing conditions, frost depth, and any required reinforcement or key details. If your designer called for stepped footings or engineered footings, this is where it must be correct.

3) Foundation forms / rebar / wall reinforcement (before concrete)

Whether you’re forming a poured wall, building ICF, or using a different engineered system, the inspector typically wants to see reinforcement and foundation details before concrete is placed. That’s where the “you can’t inspect what you can’t see” rule matters most.

If you’re doing ICF, a lot of the success comes down to clean bracing, straight walls, correct bar placement, and proper openings. If you want deeper ICF-specific guidance (from planning through pour day), you’ll find a pile of practical resources at ICFPRO.ca.

4) Foundation drainage / damp-proofing / weeping tile (where required)

Foundation drainage details can be inspected before backfill. They’re looking for correct drain placement, protection measures, and that the system is installed as intended. This is a high-value inspection because drainage errors don’t show up nicely—they show up as water problems later.

5) Underground plumbing (before it’s buried)

If you have plumbing under a slab (common in basements, slabs, or garages), the underground rough-in is typically inspected before the slab is poured. This includes pipe sizing, slope, bedding, venting approach, test requirements, and layout relative to the plan.

6) Slab prep (project-dependent)

Some municipalities inspect slab prep: vapour barrier, insulation, reinforcement, and penetrations. This is especially relevant in slabs-on-grade and heated slabs. If your home has radiant floor heating, there can be additional checks (manifolds, pressure tests, tubing layout, and protection).

If you’re planning radiant, this cost/decision guide is useful: Cost Of Radiant Floor Heating in Ontario.

7) Framing inspection (structure + safety basics)

Framing inspection is where the inspector confirms the structure matches the approved drawings: beams, lintels, headers, spans, engineered elements, braced wall lines, stair rough framing, fire blocking, and more. If the plan calls for engineered trusses, LVLs, steel beams, or special connections, this is where mismatches get flagged.

8) Rough-in inspections: plumbing, HVAC, and electrical (often separate)

Rough-ins are where the house becomes a system: drains, vents, water lines, ducts, ventilation, combustion air, equipment locations, and wiring. Depending on your municipality and scope, building inspectors may review some of this and separate authorities may handle others (for example, electrical is often inspected under a separate authority).

The biggest “2025-era” pressure point here is coordination: intakes and exhaust terminations, ventilation layout, and ensuring that what’s on the plan is what’s on the wall. If you want a homeowner-friendly rundown of recent code context, see Ontario Building Code Changes for 2025.

9) Insulation + vapour barrier (before drywall)

This inspection is often where builds stumble, because it’s easy to be “close” and still be wrong. Inspectors may look at: insulation levels and installation quality, vapour barrier continuity, sealed penetrations, attic insulation and baffles, fire separations, and air barrier details.

10) Fire separations & life safety details (as needed)

Attached garages, furnace rooms, multi-family details, and certain stair/egress configurations can trigger specific inspection attention. Even in a single-family home, garages and mechanical rooms are common deficiency hotspots.

11) Septic inspections (if you’re not on municipal services)

If you’re on a private septic system, there are required inspections tied to that system’s installation and components. These are critical because once a septic bed is covered, it’s “out of sight” — and problems become expensive to remedy. If your build includes septic, this guide is a good companion: Septic Systems Ontario.

12) Final inspection + occupancy (the finish line has two steps)

Many homeowners assume there’s one final inspection and you’re done. In practice, some projects can have an occupancy stage (or partial occupancy) and a true final where all items are complete, documentation is in, and any outstanding deficiencies are corrected. The exact approach depends on municipality and project type.

Common inspection fails (and how to avoid them)

Inspectors don’t fail projects for fun. Most failures fall into a few predictable buckets. If you avoid these, your build runs smoother.

Occupancy vs final inspection (why the last 10% feels like 40%)

In many builds, “occupancy” is essentially permission to live in the home once key life-safety and functional requirements are met. “Final” is where every required item is complete: guards, stairs, finishes, exterior grading where required, documentation, and any outstanding deficiencies from prior inspections.

The reason homeowners feel the last stage drags is that the remaining items are often scattered: a missing handrail here, a guard issue there, one last piece of ventilation, a document, a final septic sign-off, and so on. Good project management is what prevents this from turning into a month of “we’ll be there Tuesday.”

How to pass inspections without delays (the builder playbook)

Here’s the simple, repeatable approach that keeps inspections from becoming a bottleneck:

What if something goes sideways?

Sometimes an inspection issue becomes a dispute — not with the inspector, but between owner and builder, or between trades. If you ever land in a serious “non-performance” situation, it helps to understand Ontario’s legal framework around construction projects. This article is useful background reading: How to Register a Construction Lien in Ontario. (Most homeowners never need it — but knowledge changes conversations.)

Two external resources worth bookmarking (official + deep reference)

If you want the official government starting point for building code information and updates, the Government of Ontario’s building code resources are the correct place to begin: Ontario Building Code information (Ontario.ca).

And for those who like the “full reference document” (or you want to verify a detail your designer is citing), the Building Code Compendium PDF is a good deep reference: Ontario Building Code Compendium (PDF).

Disclaimer: This guide is educational and intentionally practical. Always confirm your municipality’s required inspections and any project-specific requirements with your building department and qualified designers/trades.