The recently published 2010 National Model Construction Codes contain close to 800 technical changes that were approved by the Canadian Commission on Building and Fire Codes. Summarized below are the most significant technical changes. Free online presentations providing more detailed overviews of these changes will be available in February 2011 on the national codes web site (www.nationalcodes.ca). They replace the cross-country seminars traditionally offered during past model code launches.
National Building Code of Canada (NBC)
Part 3: Fire Protection, Occupant Safety and Accessibility
Protection Against Falls from Residential Occupancy Windows. A requirement has been introduced providing for a guard or a mechanism that prevents a window from opening more than 100 mm.
Part 4: Structural Design
Live Load Due to Use and Occupancy. Crane and vehicle loads are more explicitly defined. The minimum live loads for areas in arenas, grandstands and stadia having fixed seats with backs has been reduced and the requirement extended to include churches, lecture halls and theatres.
Wind Loads. Buildings with very long periods of vibration, one of the most important factors determining how a structure will respond to external forces, must now be designed by experimental methods; dynamic calculations are no longer acceptable.
Earthquake Design. Revisions were made to requirements related to site properties, irregularities, steel structures, static and dynamic procedures, and diaphragms.
Part 5: Environmental Separation
Structural Loads. Seismic effects will now be taken into account only for post-disaster buildings (i.e. buildings essential to the continued provision of services in the event of a disaster).
Part 6: Heating, Ventilation and Air-conditioning
Ventilation. New requirements relating to acceptable building air ventilation have been added. They specify maximum levels of particulate matter, ground-level ozone and carbon monoxide in air for building ventilation purposes.
Part 9: Housing and Small Buildings
Secondary Suites in Houses. Changes in requirements include limiting their size, making “secondary suite” a defined term, and inserting “house” into many requirements that previously only applied to dwelling units.
Lateral Loads. A probabilistic-based approach for exposure to wind and seismic forces using environmental load data was added, as were prescriptive requirements for high-load areas. The concept of braced wall panels was introduced. Requirements for fastening and framing based on local wind and seismic conditions have also been added.
Low Permeance Materials in the Building Envelope. A simplified approach to requiring the correct position and properties for low air and vapour permeance materials in building envelopes was introduced.
Garage Floors. Inconsistencies were resolved in the requirement that garage floors be sloped to the exterior to limit heavier-than-air gas inflow into habitable spaces below the garage floor level.
Tables A-9.10.3.1.A. and A-9.10.3.1.B. Two footnotes were added to clarify requirements for adhesives employed in finger joined studs and prefabricated I-joists used in assemblies requiring a fire-resistance rating in buildings.
Parts 3 and 9
Spatial Separation between Buildings. Additional fire protection requirements were introduced relating to the construction of all buildings and houses in proximity to one another or to the property line.
Fire Alarm Systems and Smoke Alarms. New requirements and clarifications were introduced for smoke alarm placement, commissioning of life safety and fire safety systems, and when fire alarm components must be installed.
Penetrations Through Fire Separations. Definitions for “fire stops” and “fire blocks“ have been added, as were several changes addressing penetrations through fire separations. Requirements involving attics that don’t have sprinklers were clarified.
Exit Signs and Markings. Requirements addressing green pictograms conforming to ISO standards and photoluminescent exit signs were introduced.
Stairs, Ramps, Handrails and Guards. A set of 31 changes address inconsistencies between Part 3 and Part 9 regarding the respective requirements for stairs, ramps, handrails and guards. Many clarifications were also added.
Parts 5 and 9
Windows, Doors and Skylights. A new, harmonized North American standard for windows, doors and skylights is now referenced in the NBC. This resulted in a substantial reorganization of Sections 9.6. and 9.7.
Sealant Standards. Outdated standards for sealants were replaced with current ASTM standards that address relevant product categories and contain equivalent or similar performance criteria.
Parts 5, 6 and 9
Radon. The new Health Canada guideline of 200 Bq/m³ for indoor radon concentration has been referenced in the Appendix. Parts 5 and 6 now require that engineers and designers consider radon protection in their designs. Air barrier requirements in Part 9 were consolidated and prescriptive measures on providing a rough-in for a future radon mitigation system added.
Appendix C, Table C-2
Seismic Values and Climatic Data. Climatic data and localities were updated and the equation derived to fit the seismic observational data was improved.
National Fire Code of Canada (NFC)
Leak Detection and Monitoring. Changes dealing with leak detection and monitoring, as well as handling of certain dangerous goods, have been introduced. Existing requirements relating to the detection and monitoring of storage tanks, sumps, and piping systems containing flammable and combustible liquids were revised and new ones added.
Storage of Flammable and Combustible Liquids in Buildings. Limits to quantities of flammable and combustible liquids stored within buildings have been updated. New passive and active fire protective measures have been added.
Fire Safety at Demolition and Construction Sites. Adjacent buildings or facilities must now be protected from fires originating from demolition or construction sites. Requirements for fire safety plans and fire department access to sites were improved. Specific requirements on the commissioning and decommissioning of standpipe systems, as well as restrictions on rooftop bitumen kettle placement, have been added.
NBC and NFC
Care Occupancies (NBC Part 3, NFC Part 2). A new occupancy classification for residential care facilities has been created (Group B3 occupancy) that relaxes requirements for smaller care occupancies having a limited number of occupants. New construction, sprinkler, emergency power and fire alarm requirements were added.
Relocation of technical requirements. To draw a clear line between the roles of the NBC and the NFC, building design requirements presently in the NFC were moved to the NBC (except for spill control measures). Appropriate cross-referencing between the two codes was added.
National Plumbing Code of Canada
Water Pipe Sizing. Pipe sizing requirements were updated to accommodate the current standard practice of using water-conserving appliances and fixtures in buildings and facilities.
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