Navigating the 2024 Ontario Building Code Changes

With the new year just around the corner, we are expecting major revisions to the Ontario Building Code coming into effect on January 1, 2025. Referred to as the “largest ever provincial building code revision”, these codes are to ensure safety and structural integrity, and reduce casualties to its occupants, environment, and building envelope, while also promoting consistent construction standards. Among the many changes coming into effect, there is a notable impact on farm buildings. The goal of these changes is to harmonize with the 2020 National Building Code and be responsive to modern farm practices while providing safety for farm buildings consistent with other buildings.  

Farm building requirements will be divided into small and large buildings, with its primary focus being large farm buildings that exceed 600 square meters or more than three storeys in building height. For smaller farm buildings, they can continue to conform to the 1995 National Farm Building Code.

Detailed under “Part 2 Farm Buildings” the key changes relate to fire risk, egress, ventilation and geographic climate loads (snow, wind and seismic). Classified as Group G (agriculture), new farm buildings will be broken down into G–1 to G–4 with G–1 being High Hazard.  

Group G, Division 1 occupancy:

  • High Hazard 
  • Contains sufficient quantity of highly combustible and flammable or explosive materials 
  • Constitutes a special fire hazard 

Group G, Division 2 occupancy:

  • Not elsewhere classified in Group G 
  • Ex. Animal housing, milking facilities, farm workshops, etc. 

Group G, Division 3 occupancy:

  • Greenhouses 

Group G, Division 4 occupancy:

  • No human occupancies
  • Ex. Biomass facilities, digesters, etc. 

The changes coming into effect are as follows: 

Section 2.2. Fire Protection and Occupant Safety 

  • 2.2.2 
    • Permitted with some prohibitions. Fire separations are generally required between occupancies. 
    • New Table 2.2.1.4. dictates fire separations between major occupancies 
    • Subsidiary occupancies permitted with reduced fire separation requirements (maximum 1-hr FRR). 
    • Non-agricultural major occupancies are designed as per the requirements of OBC – Part 3, which is part of the already established OBC. 
    • Exception: if non-agricultural occupancies are less than 10% of floor area in a given storey, they don’t need to be considered a major occupancy for building classification purposes (except for F1)  
    • Residential major occupancy allowances in comparison with previous legislation as a permitted use for G-2 and G-3 
    • Farm buildings with multiple Division G classifications to adhere to 2.2.2.1 (1) by utilizing the building height and area to determine requirements. 
  • 2.2.2 – Building Size

    Building Size and Stories 

     

    < 600 m², up to 3 storeys 

    Design to 1995 NFBCC 

    Unlimited building area, up to 3- storeys 

    Combustible Construction, no sprinklers, no fire ratings on floors 

    Unlimited building area,  4 or more storeys 

    Sprinklered, 45 min. fire separations for all floors 

     

  • 2.2.3 – Fire Alarm and Detection Systems 
    • Fire alarms only required when buildings are NOT sprinklered  
    • Fire alarms required in UNSPRINKLERED farm buildings: 
    • With two or more storeys, or 
    • Occupant load exceeding 150 
Major Occupancy Occupant load Storeys 
G-1 > 25 people ** Greater than 1-storey is always sprinklered 
G-2 or G-3 >150 people >1 Storey 
G-4 Not required Not required 
  • 2.2.6.1 – Egress
    • Two egress doors are required from a room based on room area, travel distance and sprinklered or non-sprinklered. One egress door is permitted in certain instances (small rooms)
  •  2.2.7 – Exits
    • Typically, exits need to be an exterior door that swings in the direction of exit travel 
      • Exit doors for G-2 occupancies housing animals don’t need to swing outwards 
      • Door hardware needs to be operable with one hand and require only one releasing operation 
    • A minimum of two exits are typically required 
      • Locations determined by travel distance  
      • Max 60m in non-sprinklered G-2 building 
    • G-3 (greenhouses) are permitted to space exits at 60m along the perimeter with clear aisles leading to the exits 
    • G-4 occupancies don’t need exits 
      • No human occupancy 
    • Proposed Change 1784 – Sill Height for Exit  
      • Maximum sill height has been specified for openable panels or windows utilized as exits 
      • Due to the unique nature of farm buildings, this will maintain the integrity of livestock areas while providing access in an emergency scenario  
    • For livestock areas the location of the sill height is important to ensure deterrence of access by livestock, deter escape and or for biosecurity reasons. Locations determined by travel distance. 
      • A minimum sill height of 1.5m is proposed to ensure the above while allowing egress for occupants in an emergency 
    • Footholds can be created by way of notches in concrete walls, secured lumber or similar ledges / support infrastructure to allow access to the exit panel or openable window with minimal cost implications 
  • Other Fire Protection Topics
    • Fire department access will be required through a street, private roadway or yard to access the farm building. [2.2.4.1.] 
    • Emergency lighting with backup power required (if lighting is provided) [2.2.5.1.] 
    • Exits signage to conform to 3.4.5.1. [2.2.7.10.] 
    • Required if more than 2 storeys, occupant load greater than 150 
    • Spacing of attic fire blocks to be based on area (900 m²) [2.2.1.8.(3)] 
    • Spatial separation requirements removed (except for pesticide storage) 
    • Likely to be added in to 2025 NBC (under consultation) 
    • Spatial separation requirements for non-farm buildings still relevant 
    • Other applicable legislation (ex. Zoning setbacks) still apply 
    • Portable fire extinguishers required pre OFC [2.2.4.3] 
  • Reduced Requirements
    • Removal of maximum fire compartment sizes 
    • Removal of 30m spatial separation to property lines, centerline of public thoroughfares or other building types 
    • Fire blocking in concealed spaces of walls or ceilings 
  • Not Required
    • Barrier-free design 
    • Resources conservation 
    • Plumbing (washroom requirements) 
    • Environmental separation 
    • Radon mitigation 

Section 2.3. Structural Loads and Procedures 

  • Section 2.3. Structural Loads and Procedures 
  • 2.3.1.1 
    • Design as per Part 4 (with some exceptions) 
    • Subsurface investigations of the farm building site can be performed by a suitably qualified person (soil bearing conditions) 
  • 2.3.2.1 – Specified Live Loads 
    • NFBC loads maintained yet simplified 
    • Increase to loads for machinery and to account of actual size of farm equipment being used today 
    • Low importance factor except for manure storage 
    • Liquid manure tanks to be designed with normal importance category 
  • 2.3.2.4 – Farm Machinery 
    • Maintained, plus new loads for large equipment 
    • Reference to Part 4 for point loads 
  • 2.3.3 Structural Design – Snow 
    • General principles maintained 
    • Updated to current OBC standard with same 50-year return period 
    • NFBC modified System Factors for Sawn Lumber have been removed. System factors to be as per CSA O86 without modification [NFBC 2.3.1.2]. 
    • Current O86 wood standards apply and do not allow system factor with 4’-0” truss spacing. 
    • Unobstructed slippery roof factor still applies. 
    • Minimum roof snow load for greenhouses increased from 0.7 kPa to 1.0 kPa. 
    • The minimum requirements for use of this reduced snow load now include: 
    • Minimum heating system to 10°C with backup power. 
    • Drainage system to remove water 
  • 2.3.3.1 & 4.1.7. Structural Design – Wind 
    • Structural design for wind to be as per Part 4 with no farm-specific exceptions. 
    • Design wind loads for farm buildings increased from a 1-in-10 year return period (NFBC) to a 1-in-50 year return period (OBC) 
    • Small Farm Buildings may still use q(1/10) from NEW OBC SB-1 climatic data 
    • Changing from q(1/10) to q(1/50) results in a 25% – 35% increase in wind load, depending on the geographic location 
  • 2.3.4 Structural Design – Seismic 
    • Global exemption for earthquake design for farm buildings has been removed. 
    • Default is to design for seismic loads, with two exemptions. 
    • Farm buildings need to not be designed for seismic loads where: 
    • Seismic category is SC1 (areas with very low seismic activity,) or 
    • Seismic category is SC2 (low seismic activity) and RdRo factor greater than 3 
    • For this seismic screening calculation only, a Site Class D may be assumed without a geotechnical investigation. 
  • 2.3.1 Structural Design – Procedure 
    • OBC importance factor for limit states design of 0.8 maintained. 
    • Allowable Stress Design method has been deleted. 
    • NFBC provisions for load testing have been removed. Any testing to be as per material standards. 

Section 2.4. Heating, Ventilation and Air-Conditioning 

  • Ventilation to be as per Part 6 with a few exceptions 
  • Provisions for controlled atmosphere storage and silo gases 
  • Liquid manure storage tanks below barns shall be ventilated to control explosive risk. Minimum 2 air changes per hour. 
  • Fuel fired appliances to be separated from the rest of the barn.  

What are the cost implications?  

With these new changes coming into effect, the standards for building materials such as stricter fire and material testing protocols, may require builders to use more expensive and/or higher quality materials. Its impact on cost are due to the improvements in safety and performance.  

Fire Protection and Occupancy Safety: 

We can see the rise in Fire suppression equipment since 2014 – primarily with our focus being on its small jump leading into the new 2024 OBC, we can expect a 2.49% increase in price due to the needs of fire suppression systems 

The price of concrete, commonly used in the construction of fire separation systems, are expected to increase by 20.43% going into the 2025 year, as seen in the image below. This increase in price may be due to requirements of fire separation between occupancies. 

Structural Loads and Procedures: 

Wood, plastic and composites have an intense decrease in price, predicted to drop 24.57% in 2025. This may be due to the deletion of load testing methods and stress design methods, builders may find alternative materials for a better price that could be more powerful and efficient to their farm buildings. 

Heating, Ventilation and Air-Conditioning: 

The increase of price in HVAC systems coming into 2025 is 4.48%. The new building code speaks of the needs of these systems and its presences within a farm building, especially those with storage tanks and other related chemicals. They must have consistent ventilation to meet code.  

Considering all this, the new 2024 Ontario Building Code is being put into effect to not only reduce risk to farmers and workers, but to also enhance safety, efficiency, and performance to all buildings moving forward. .Officially, these new codes are effective starting January 1, 2025, thought there will be a 3 month grace period until March 31, 2025, for designs that are currently underway or will be before the end of 2024. Permit applications submitted with the use of the 2012 OBC will be allowed for extension if applicants demonstrate their working drawings are substantially complete by Decembre 31, 2024. Permit applications submitted after that must use the new 2024 OBC. 

General Comparison 
Before (2012 Ontario Building Code) After (2024 Ontario Building Code) 
Part 2 – Reserved Part 2 – Farm Buildings 
Uses 1995 NFBC Harmonized with 2020 National Building Code 
small and large farm building designs use 195 NFBC Large farm buildings use 2024 OBC Small buildings can continue with 1995 NFBC 
NO specified occupancy classification for farm buildings Group G classification (agricultural) 
Fire Protection and Occupant Safety Comparison 
Before (1995 National Farm Building Code) After (2024 Ontario Building Code) 
NO sprinkler requirements Sprinklers based on building size and occupant load 
NO fire alarm requirements Fire alarms required in non-sprinklered buildings 
2 exit doors spaced remotely at opposite ends of the building 2 exit doors are required based on room area, travel distance, sprinklered or non-sprinklered 
Exit door swing direction not specified Door swings the direction of exit travel (Not required in G-2 occupancy) 
NO sill height specified A minimum sill height of 1.5m to allow egress during an emergency 
30m spatial separation to property lines Spatial separation requirements removed 
No fire extinguisher requirements Fire extinguisher required per OFC 
Fire blocking in concealed spaces of walls or ceilings; maximum horizontal dimensions are 6m Fire blocking in concealed spaces of walls or ceilings; maximum horizontal dimensions are now 20m 
Structural Loads and Procedures Comparison 
Before (1995 National Farm Building Code) After (2024 Ontario Building Code) 
Minimum specific live loads on a floor or ceiling:   Cattle: 3.5 kPa Sheep: 1.5 kPa Swine: 2.5 kPa Horses: 5.0 kPa Poultry: 2.0 kPa Greenhouses: 2.5 kPa Minimum specific live loads on a floor or ceiling:   Cattle: 5.0 kPa Sheep: 2.5 kPa Swine: 3.5 kPa Horses: 5.0 kPa Poultry: 2.0 kPa Greenhouses: 2.5 kPa 
Equipment up to 700 kg used for manure cleanout shall be designed for a two-wheel live load of 4.0 kN Equipment up to 1000 kg used for manure cleanout shall be designed for a two-wheel live load of 6.0 kN  
Live load on an area of floor used for farm machinery traffic shall be not less than 7.0 kPa Live load on an area of floor used for farm machinery traffic shall be: For vehicles not exceeding 4000 kg, not less than 2.4 kPa For vehicles between 4000 kg – 9000 kg, not less than 6 kPa For vehicles exceeding 9000 kg, not less than 12 kPa 
Minimum roof snow load for greenhouses is 0.7 kPa Minimum roof snow load for greenhouses increased to 1.0 kPa 
Specified strengths for sawn lumber members in a system of 3 or more, spaced not more than 1220mm apart and arranged to mutually support the applied load Modified system factors for sawn lumber have been removed 
Design wind loads for farm buildings are a 1-in-10 year return period  Design wind loads for farm buildings have been increased to a 1-in-50 year return period 
Farm buildings need not be designed for loads due to earthquakes Farm buildings need not be designed for seismic loads where: Seismic category is SC1 or, Seismic category is SC2 and RdRo is greater than 3 
Allowable stresses for masonry construction in working stress design are permitted to be increased by 25% Allowable stress design method has been removed 
Minimum 3 representative sample assemblies to be tested Load testing has been changed to be as per material standards 
Heating, Ventilation and Air-Conditioning Comparison 
Before (1995 National Farm Building Code) After (2024 Ontario Building Code) 
Only signage code for controlled atmosphere storages Provisions regarding its ventilation and oxygen content has been added 
Only signage code for liquid manure tanks Liquid manure tanks must be ventilated to control risk. (min. 2 air changes per hour) 
Only signage code for silos  Silos must have exhaust ventilation to remove air (min. 3 air changes per hour) 
Fuel fired appliances to be in a service room or service space Fuel fired appliances to be separated from the rest of the barn 

This document is for general information only and is not an official copy of the 2024 Ontario Building Code and the law that governs it. Always refer to the official Building Code. https://www.ontario.ca/page/2024-ontario-building-code

References 

[1] K. Sutton and A. Forristal, “Coming soon: Ontario’s New Building Code (January 1, 2025),” McMillan, https://mcmillan.ca/insights/coming-soon-ontarios-new-building-code-january-1-2025/ (accessed Nov. 1, 2024).  

[2] OAA News, News & insights – Ontario’s New Building Code released with revised structure, https://oaa.on.ca/whats-on/news-and-insights/news-and-insights-detail/Ontarios-New-Building-Code-Released-with-Revised-Structure (accessed Nov. 1, 2024).  

[3] “OFA submission regarding proposed change to the 2025 national construction codes relating to farm buildings,” Ontario Federation of Agriculture, https://ofa.on.ca/resources/ofa-submission-regarding-proposed-change-to-the-2025-national-construction-codes-relating-to-farm-buildings/ (accessed Nov. 1, 2024).  

[4] Jon, “Building code update should be seen as a positive,” Elite Agri Solutions, https://eliteagrisolutions.ca/articles/building-code-update-should-be-seen-as-a-positive/ (accessed Nov. 4, 2024).  

[5] Ontario, “2024 Building Code Technical Bulletins” (July 2024) https://www.cfba.ca/images/newsmanager/newsfiles/2024-07-16-13-29-50-DbtI-1375-13752024%20Building%20Code%20Technical%20Bulletins%20(All%20Parts)%20July%202024.pdf (accessed Nov. 4, 2024) 

[6] L. Boonstoppel, “Farm Building Code will get a makeover January ’25,” CFBA, https://www.cfba.ca/images/newsmanager/newsfiles/2024-05-14-21-19-33-4PKW-1352-1352Farm%20Code%20FARMB_001_0507.pdf (accessed Nov. 4, 2024).