Ontario Building Permit Process: Engineer-Led Filing to Occupancy

When Is a Building Permit Required?

Under the Building Code Act, S.O. 1992, c.23, Section 8, no person shall construct or demolish a building or cause a building to be constructed or demolished unless a building permit has been issued. The Act defines "construct" broadly to include erection, installation, extension, material alteration, or material repair. Key trigger scenarios for structural permit requirements:

• New building construction of any kind
• Any addition (horizontal or vertical) to an existing building
• Structural alterations: load-bearing wall removal, beam additions, column removals, floor openings
• Foundation work: underpinning, new footings, basement lowering
• Change of use that triggers a different OBC occupancy classification
• Demolition (separate permit required)

Ordinary maintenance and repair that does not involve structural elements, regulated mechanical systems, or material alteration of the building generally does not require a permit. However, even cosmetic work that conceals structural elements (drywalling over exposed beams, tiling over a structural slab crack) may require a permit if those elements are being altered. When in doubt, have your engineer or permit consultant confirm the scope with the municipality before work starts.

The Legal Framework: Building Code Act & OBC

Ontario's building permit system operates under two instruments:

• Building Code Act (BCA), S.O. 1992, c.23: The enabling statute that establishes the building permit system, the powers of chief building officials (CBOs), mandatory inspection stages, and the consequences of non-compliance
• Ontario Building Code (O.Reg 332/12): The technical standard that governs how buildings must be designed and constructed. The OBC is divided into Divisions A (objectives), B (acceptable solutions / technical requirements), and C (administrative provisions)

Enforcement is by the municipal building department, led by the CBO. Provincial oversight is through the Ministry of Municipal Affairs and Housing (MMAH). PEO regulates the engineers who design and review structural systems. These three agencies — municipality, province, and professional regulator — intersect in every building permit process.

Preparing for Permit Application

The preparation phase is where most permit delays originate. Before applying:

1. Confirm the project scope and OBC classification. Is this a Part 9 (small residential), Part 3 (major occupancy), or Part 4 (complex structural) project? This determines which drawings, engineer requirements, and review timelines apply.
2. Engage your design team early. For Part 3 buildings, you will need an architect and structural engineer at minimum. Mechanical and electrical engineers are required where those systems are present.
3. Check zoning compliance. Your municipal zoning by-law may restrict building height, setbacks, lot coverage, and parking. Zoning conflicts must be resolved (through minor variance or re-zoning) before a building permit can be issued.
4. Commission a geotechnical investigation. For any new structural foundation or underpinning, a soils investigation by a geotechnical engineer is required before the structural engineer can finalize the foundation design.
5. Check for Heritage or Conservation Authority overlap. Properties on the Ontario Heritage Register or within regulated floodplains or river valleys require additional approvals before a building permit can be issued.

Required Documents

Submitting the Application

Applications are submitted to the municipal building department of the municipality where the property is located. In practice, owners usually authorize their engineer or permit consultant to prepare and coordinate that filing. In Toronto, most Part 3 applications are submitted electronically through Toronto Building's ePLAN portal, and Asvakas can manage that process on the project's behalf.

At submission, the building department performs an intake review to confirm all required documents are present. If the application is incomplete, it is returned with a deficiency list. The statutory review clock begins only once the municipality accepts the application as complete.

Review Timelines Under the BCA

The Building Code Act sets prescribed review targets that vary by building class. Simpler residential applications have shorter service targets than large Part 3 or specialized projects, but those targets only apply to complete submissions and do not eliminate the possibility of objections or resubmission cycles.

In practice, total time to permit depends on submission quality, coordination with zoning and outside approvals, and the municipality's current review queue. Complex projects should be scheduled on the assumption that at least one round of comments and revised drawings may be required.

Conditional Building Permits

Section 8.1 of the Building Code Act allows a chief building official to issue a conditional permit before all required drawings are complete, provided:

• Working in advance is necessary because of unreasonable delays
• The outstanding design issues are not related to the safety of persons
• The owner has entered into a written agreement with the municipality accepting full liability for any remediation if the full design is subsequently found non-compliant

Conditional permits are frequently issued for the foundation and below-grade portion of a project while above-grade architectural coordination is still ongoing. They allow a developer to start construction months earlier than waiting for a full permit — a significant schedule benefit for large projects.

Once the Permit Is Issued

The building permit must be posted prominently on site before construction commences. The approved drawings must be kept on site at all times during construction. Any change to the approved design — even minor field changes — requires either a formal permit amendment or, for minor adjustments, a Revision to Approved Permit submission reviewed by the building department before the change is made.

Mandatory Construction Inspections

OBC Division C, Article 1.3.3 requires mandatory building inspections by the municipal building inspector at prescribed stages. The permit will specify the required inspection stages, which typically include:

• Excavation / before footings: Building inspector confirms excavation depth, soil bearing conditions, and that no work below grade has been concealed
• Foundation walls (before backfill): Confirms foundation wall construction, waterproofing, and drainage
• Structural framing (before close-in): Confirms structural framing members, connections, and fire stopping
• Insulation and vapour barriers (before drywall): Confirms thermal and air barrier continuity
• Final inspection: Confirms all work is complete and the building is ready for occupancy

The owner or contractor must give the building department the notice required by the permit or the local municipality before each inspection stage. Do not cover or conceal any element before the required inspection has been completed and noted as satisfactory.

General Review by the P.Eng.

For Part 3 and Part 4 buildings, the structural engineer is separately obligated to perform General Review — periodic professional site visits at structural construction stages. This is distinct from the municipal builder inspector's visit and serves a different function. (See our article on PEO General Review Requirements for a full explanation.) General review results in a Schedule 2 completion certificate that the CBO requires before issuing the occupancy permit.

Obtaining the Occupancy Permit

An occupancy permit (or certificate of occupancy) authorizes the building to be used for its intended occupancy. To obtain it:

1. All construction must be complete (or substantially complete with minor deficiencies that do not affect safety)
2. Final inspection by the municipal building inspector must be satisfactory
3. Schedule 2 letters must be submitted by all professionals listed on Schedule 1 (structural, mechanical, electrical, architectural engineers)
4. All applicable permits and approvals (fire Marshall, public health, utility connections) must be in order

In some municipalities, an interim occupancy may be granted for completed floors of a multi-storey building before the entire building is fully complete. The building must meet all applicable safety requirements for the occupied portion before interim occupancy is permitted.

Consequences of Building Without a Permit

Constructing without a required building permit in Ontario is a violation of the Building Code Act and carries significant consequences:

• Stop Work Order: The CBO can order all work to stop immediately
• Order to Demolish: In serious cases, the CBO can order demolition of non-permitted work
• Provincial Offences Act fines: The Building Code Act provides for significant fines and prosecution risk for unauthorized construction
• Insurance implications: Unpermitted work may void property insurance claims related to that work
• Property transaction complications: Unpermitted work discovered during a real estate transaction will require disclosure, and the cost of legalizing or removing the work typically falls on the seller