Ontario Building Code vs. Ontario Fire Code for existing buildings: A technical guide

Navigating life safety regulations for existing buildings in Ontario requires understanding two primary, complementary regulatory frameworks: the Ontario Building Code (OBC) and the Ontario Fire Code (OFC). 

Whether managing renovations, executing a change of use, or maintaining daily operations, design professionals, engineers, and property managers must establish clear code jurisdiction early in the project lifecycle.

Code references throughout this guide refer to Division B of the 2024 Ontario Building Code unless otherwise stated.

What building and fire safety codes apply to an existing building in Ontario?

For existing buildings in Ontario, code application depends on the nature of the work being performed:

• Ongoing operations & maintenance: The Ontario Fire Code (OFC) applies continuously to all existing buildings. In some cases, the code may mandate additional construction for the control of hazardous spaces or retrofit upgrades for higher-risk occupancy buildings. 
• Renovations, alterations, or additions: The Ontario Building Code (OBC) applies to new physical work, such as renovations or remodelling, and only mandates work in existing buildings when the new proposed work reduces the performance of existing building systems.
• Change of use: The Ontario Building Code (OBC) applies when a change in occupancy increases the operational hazard, even if no physical construction takes place.

Ontario Building Code (OBC) vs. Ontario Fire Code (OFC)

Ontario fire and life safety regulations are administered by the Ministry of Municipal Affairs and Housing (MMAH) for building codes under the Building Code Act, 1992 and the Office of the Fire Marshal (OFM) under the Ministry of the Solicitor General via the Fire Protection and Prevention Act, 1997.

Feature	Ontario Building Code (OBC)	Ontario Fire Code (OFC)
Primary Scope	Design, construction, material alteration, and change of use.	Ongoing operation, maintenance, and fire hazard control.
Application Period	Point-in-time (at permit issuance and during construction).	Continuous throughout the operational lifecycle of the building.
Existing Buildings	Triggers upon physical work or occupancy change (via Part 11 or Part 10).	Always applies; mandates proactive maintenance and retrofits.
Governing Authority	Ministry of Municipal Affairs and Housing	Office of the Fire Marshal
Enforcement	Local Chief Building Official (CBO), Plan Reviewers, Inspectors, or other delegated authority.	Local Fire Chief, Inspectors, and Fire Prevention Officers.
Governing Legislation	Building Code Act, 1992	Fire Protection and Prevention Act, 1997

Actions that trigger enforcement of the Ontario Building Code for existing buildings

The Ontario Building Code (O. Reg. 163/24) does not require existing, unaltered buildings to be upgraded to current construction standards. Building codes evolve over time, but older structures remain legally compliant based on the applicable standards at the time of construction.

Design/construction on existing buildings

When additions, structural alterations, or physical renovations are proposed, the Ontario Building Code applies to the new work. The extent of Ontario Building Code application on the remaining unaltered portions of the building depends on the proposed scope of work, the building’s age, and the original construction and use of the building.

Change of use of existing buildings

When the occupancy or use of a space changes, such as converting a light industrial space into an assembly occupancy, the Ontario Building Code applies (under section 10 of the Building Code Act). Even if no construction is undertaken, a change of use that introduces a higher hazard level requires an evaluation to confirm compliance with building safety rules.

No construction or change of use

If an existing building maintains its current use without physical alterations or structural additions, the OBC is not applicable. The building is governed solely by operational maintenance and retrofit standards under the OFC.

What part of the Ontario Building Code is relevant for buildings with additional construction or change of use?

When physical construction or a change of use is proposed, compliance for existing buildings that are at least 5 years old is evaluated under Part 11. Part 11 provides a framework that allows existing performance levels to be preserved without forcing full compliance with modern new-construction rules, provided existing levels of life safety are not compromised. Part 10 similarly applies to a change of use where no construction is proposed.

Where proposed changes reduce performance or increase the hazard, Part 11 establishes requirements for compensating construction (such as enhanced fire separation, add-on suppression, or localized exit and access to exit upgrades). This evaluation model is vital for historical assets protected under the Ontario Heritage Act and adaptive reuse projects where preserving original architectural elements is required or desired.

Which measures from the Ontario Fire Code apply to existing buildings?

The Ontario Fire Code (O. Reg. 213/07) applies continuously to all existing buildings in Ontario from the day they are occupied. Hazardous spaces and retrofits require additional measures. Here is some of what you need to know to make your building compliant. 

Fire code compliance for ongoing use/operation/maintenance

The OFC mandates regular testing, inspection, and maintenance of active and passive fire protection systems. Responsibilities under the OFC include, but are not limited to, the following:

• Maintenance and inspection of fire alarm, sprinkler, and standpipe systems.
• Maintaining clear, unobstructed paths of egress and fire separation integrity.
• Implementation of approved Fire Safety Plans and emergency procedures.
• Control of combustible waste, flammable storage, and localized ignition sources.

Fire code compliance for “hazardous spaces”

The design and operational protection of hazardous spaces are governed directly by the OFC for both new and existing buildings. Where an existing space stores, handles, or uses significant quantities of flammable or combustible liquids, or hazardous gases, or involves hazardous processes, like spray operations,  the OFC may require localized physical upgrades, regardless of whether construction or a change of use is occurring.

Fire code compliance for older assembly, residential, and vulnerable occupancies

Part 9 of Division B of the OFC outlines mandatory retrofit requirements that apply retroactively to specific older buildings. Introduced following historical post-fire investigations (detailed in the 2026 Fire Code Compendium), Part 9 mandates upgrades to life safety in older assembly, health care, residential, or vulnerable occupancies (including care facilities, and retirement homes regulated under the Retirement Homes Act, 2010). Across all occupancies, upgrades fall under four key areas:

• Containment: fire separations, fire walls, construction assemblies, occupancy separations, and interior finishes.
• Means of Egress: access to exits, exits, fire escapes, occupant load, and emergency lighting.
• Fire Alarm and Detection: alarm and detection systems, and voice communication systems.
• Suppression: fire department access, standpipe and hose systems, sprinkler or special fire suppression systems, and firefighters’ elevators.

Property owners must maintain historical documentation demonstrating OFC compliance in accordance with Subsection 1.1.2 of Division B of the OFC. Changes in municipal fire prevention personnel can lead to renewed scrutiny of legacy “deemed to comply” decisions. In complex cases, engineering evaluations, such as a Life Safety Study prepared under Subsection 9.1.4. of Division B of the OFC, are required to verify acceptable performance.

Do all buildings in Ontario fall under the Ontario Building Code?

No, there are some exceptions where buildings in Ontario are not, or not solely, regulated by the Ontario Building Code. While most buildings in Ontario fall under provincial jurisdiction, specific legal exceptions exist:

• Federally regulated: Building construction on federal land, crown properties, military installations, or on property occupied by other federally regulated industries (e.g., airports, banks) are exempt from provincial code legislation. Federally regulated buildings are typically governed by the National Building Code of Canada (NBC) by virtue of Canada Occupational Health and Safety Regulations made under the Canadian Labour Code and real property standards under the Treasury Board of Canada Directive on the Management of Real Property.
• First Nations jurisdiction: Buildings on Reserve Lands fall under the sovereign jurisdiction of First Nations under the Indian Act. Provincial codes do not directly apply unless adopted through specific Band Council resolutions or required by policy or project requirements, such as specific stipulations for some funding arrangements.
• Multiple codes: Where projects combine funding, ownership, or oversight from multiple levels of government, conflicting code provisions must be identified during pre-design. A clear hierarchy of applicable standards should be established before finalizing the design criteria.

What national model codes apply to Ontario buildings?

Canada relies on a national model code system developed by national consensus bodies, which individual provinces modify and enforce. Model codes do not directly apply to any building unless adopted through applicable regulatory frameworks. 

The Canadian Board for Harmonized Construction Codes (CBHCC)

The Canadian Board for Harmonized Construction Codes (CBHCC) produces national “model codes,” including the National Building Code (NBC), National Fire Code (NFC), National Plumbing Code (NPC), and National Energy Code for Buildings (NECB). Model codes carry no direct legal authority until enacted by provincial or territorial legislation. The CBHCC publishes a provincial/territorial adoption tracking table, but local provincial regulations take legal precedence.

Ontario’s adoption of the model codes

• Building code: Ontario adopts an amended version of the National Building Code. O. Reg. 163/24 aligns approximately 70% of Ontario’s technical requirements with the 2020 NBC framework while maintaining Ontario-specific technical variations. 
• Fire code: The Ontario Fire Code (O. Reg. 213/07) operates as a standalone provincial regulation under the Fire Protection and Prevention Act, 1997 and does not automatically incorporate updates from the National Fire Code of Canada.

Do Ontario buildings need to comply with the National Building Code?

Unless a building is federally regulated, it does not need to comply with the National Building Code directly. However, the Ontario Building Code, which does apply, largely overlaps with and is derived from the National Building Code. 

What are Building Condition Assessments?

Building Condition Assessments (BCAs) evaluate the physical state and performance of existing building systems. 

When is a Building Condition Assessment required?

They are required or recommended in several situations including: 

• Property buyers and commercial investors prior to purchase
• Financial institutions and lenders during refinancing 
• Condominium corporations, as part of reserve fund studies, depreciation reports, and to support fiduciary responsibilities of Board Members
• Property managers and building owners preparing for preventative maintenance, or capital planning
• Social and non-profit housing groups requiring assessments to secure funding
• Institutional and portfolio manager prioritizing capital improvement grants and requests for public funding

Under O. Reg. 48/01 (Sections 27 to 33) made under the Condominium Act, 1998, formal assessments and Reserve Fund Studies are mandatory for condominium corporations to plan long-term capital repair costs.

How does a Building Condition Assessment (BCA) differ from a Code Assessment?

While RFPs for BCAs frequently request “code compliance” evaluations, standard BCAs and code assessments serve different purposes. A standard BCA supports capital investment decisions to maintain existing assets in good repair. 

The purpose of a code assessment can vary, but typically falls into three categories:

• An audit of operational maintenance activities, which aligns with “code compliance” but has little overlap with capital investment. 
• An evaluation of existing construction to identify mandatory OFC retrofit requirements. Addressing mandatory retrofit requirements is legally required but differs in scope from maintaining existing assets in good repair. 
• A gap analysis to compare existing conditions to key requirements for a new, similar building. This type of assessment is voluntary and may be merited to inform forward-looking strategic investments. While this type of assessment can inform capital decisions, it does not relate to maintaining existing assets in good repair. 

These three types of code assessments vary significantly in scope, effort, and cost from each other and from a standard BCA. As a result, standard visual building condition reviews prepared by generalists or building science consultants often omit detailed life safety analysis. Standard BCAs may overlook hidden liabilities, such as indicators of Part 9 Fire Code retrofit non-compliance, while incorrectly identifying “deficiencies” against construction requirements for new construction.

Including a qualified Code Consultant on the assessment team improves owner confidence that regulatory life safety, egress, fire separation, and accessibility compliance are being correctly evaluated alongside capital replacement cycles depending on the organization’s stated goals. 

What is a Code Consultant and when do you need one?

A Code Consultant (or Life Safety Consultant) is a specialist in fire safety, fire science, and regulatory compliance, often affiliated with professional bodies such as Professional Engineers Ontario (PEO) or the Ontario Association of Certified Engineering Technicians and Technologists (OACETT). Code Consultants establish holistic life safety strategies for complex building designs, additions, and adaptive reuse projects.

What do Code Consultants do?

• Strategy development: Documents and integrates passive fire protection (separations, compartmentation), active systems (alarms, suppression), and egress design into a unified strategy.
• Alternative solutions & engineering judgments: Code Consultants engineer alternative compliance pathways using performance-based code approaches under Subsection 1.2.1. of Division A of the OBC.
• Regulatory negotiation: Acts as a technical liaison between the design team and Authorities Having Jurisdiction (AHJs), such as municipal Chief Building Officials and local Fire Prevention Officers.

Code consultant vs. engineer of record

A Code Consultant establishes the overall life safety framework in conjunction with the design team, while the designers (e.g. Architect of Record, Engineers of Record) remain responsible for designing, and sealing and taking professional responsibility for specific architectural layouts, HVAC controls, sprinkler systems, or fire alarm schematics, etc.

When to engage a specialist Code Consultant

Engaging a Code Consultant is recommended when:

• Executing major renovations or changes of use in existing Part 3 (complex) buildings.
• Dealing with heritage buildings where modern prescriptive code compliance would compromise historic features.
• Addressing non-conforming conditions identified during real estate due diligence or Fire Code inspections.
• Developing performance-based alternative solutions.

Definitions

• Authority Having Jurisdiction (AHJ): The governmental body responsible for the enforcement of any part of this Code or the official or agency designated by that body to exercise such a function.
• Canadian Board for Harmonized Construction Codes (CBHCC): The decision-making body responsible for approving and coordinating updated content for Canada’s National Model Codes.
• Code consultant: A specialist in fire, life safety, and regulatory compliance. Often code consultants are licensed engineers or certified engineering technologists who assist project teams by formulating holistic life safety strategies, evaluating existing conditions and proposed construction under OBC Part 11, and navigating complex negotiations or alternative solutions with local building and fire officials.
• Compensating construction: Specific construction features (such as fire suppression or rated assemblies) required under OBC Part 11 to offset reductions in performance when renovating an existing building.
• Hazardous spaces: Dedicated areas within a building where high-risk materials or processes are present, such as the storage, handling, or use of flammable or combustible liquids, explosive chemicals, or hazardous gases, requiring enhanced protection systems governed directly by the Ontario Fire Code.
• Hazardous room: A room containing sufficient quantities of a substance that, because of its chemical nature, may create an atmosphere or condition of imminent hazard to health.
• Life Safety Study: A formal engineering evaluation conducted under Subsection 9.1.4. of Division B of the OFC to assess fire safety compliance and establish equivalencies in existing higher-risk buildings, where Part 9 retrofit provisions apply.
• Occupancy: The use or intended use of a building or part thereof for the shelter or support of persons, animals or property
• Office of the Fire Marshal (OFM): The provincial agency under the Ministry of the Solicitor General providing leadership in fire prevention, investigation, and fire code enforcement support in Ontario.
• Part 11 (OBC Division B): The section of the Ontario Building Code governing renovations, additions, and changes of use in existing buildings.
• Part 9 Retrofit (OFC Division B): Mandatory, retroactive fire safety requirements applied to older existing buildings under the Ontario Fire Code.
• Reserve Fund Study: A financial and physical assessment mandated for Ontario condominiums to forecast long-term repair and replacement costs for common elements. 

FAQs

1. Does renovating an existing building in Ontario automatically bring the whole structure up to current code?

The answer is yes and no. When the renovations are assessed and constructed in accordance with Part 11, the entire building does meet “current code” to the extent that it applies.

Renovations do not bring a building up to the same level of performance that would be required for a similar, newly constructed building under “current code”.

2. What triggers the application of the Ontario Building Code in an existing building?

The OBC is triggered by physical construction work (additions, structural alterations, or renovations) or a formal Change of Use that creates a higher hazard level under the code, even without physical construction.

3. How does a “Change of Use” work under the Ontario Building Code if no construction is planned?

If the use of a space changes to an occupancy with higher hazard factors (e.g., converting business office space to a restaurant assembly occupancy), section 10 of the Building Code Act requires a permit and evaluation, even if no physical construction takes place.

4. What is the main difference between the Ontario Building Code and the Ontario Fire Code?

The Ontario Building Code governs design and construction at a specific point in time (permit issuance). The Ontario Fire Code governs continuous operation, emergency planning, maintenance, and hazard mitigation throughout the building’s operational lifecycle.

5. What are OFC Part 9 Retrofit provisions, and do they apply to all older buildings?

OFC Part 9 Retrofit provisions are mandatory, retroactive safety standards targeting older buildings, primarily assembly, multi-unit residential, retirement home, and care facilities. They mandate minimum fire safety upgrades regardless of whether construction is taking place.

6. Are heritage buildings exempt from Ontario building and fire code requirements?

No, heritage buildings are not exempt. However, OBC Part 11 offers evaluation methods and compensating construction options to help preserve historic character while meeting minimum fire and life safety requirements.

7. Do provincial building and fire codes apply on federal properties or First Nations reserves in Ontario?

Generally, no. Federal properties and First Nations reserve lands fall under federal jurisdiction or local Indigenous governance. However, project contracts, funding agreements, or internal policies may require compliance with provincial standards.

8. What is an Alternative Solution under the Ontario Building Code?

An Alternative Solution is a performance-based design proposal demonstrating that a non-prescriptive construction method or design meets the intent and performance level of the code, as outlined in Subsection 1.2.1. Division A of the OBC.

9. When should a project team hire a Code Consultant for an existing building project?

A Code Consultant should be engaged during early concept design for complex renovations, changes of use, heritage projects, or whenever compliance with prescriptive building codes is difficult to achieve or alternatives are desired.