New public review of National Building Code includes energy efficiency

By Casey Edge

Codes Canada has announced a public review on changes to the National Building Code including seismic and energy efficiency from January 13, 2020 to March 13, 2020. These changes outline tiered energy performance levels for Part 9 homes and include a prescriptive option for Tier 2 construction not available in the BC Step Code. Here is a summary of what’s covered. More info and online feedback forms are available here.

National Building Code of Canada (NBC)

Large Farm Buildings (Part 2)

This introduces technical requirements for large farm buildings into Part 2 of Division B of the NBC. The four sections introduced focus on general technical requirements and classifications, fire protection and occupant safety requirements, structural design requirements, and heating, ventilating and air-conditioning (HVAC) requirements, respectively.

Accessibility (Part 3)

This improves the accessibility of buildings by revising the minimum dimensions of building elements to accommodate persons using various types of mobility devices and by addressing the visibility, detectability and ease of use of building elements for persons with reduced dexterity, vision or hearing. It also introduces requirements for visible and audible feedback signals, and visible, tactile and audible safety signage. It requires public entrances and more floor levels to be accessible and, for some occupancies, extends the barrier-free path of travel to additional storeys.

Penetrations (Parts 3 and 9)

This clarifies the requirements for the protection of penetrations through fire separations, expands protection options to include industry practices, and references test methods to increase compliance options while reducing the potential for confusion.

Earthquake Design (Part 4)

Updates seismic hazard values for various locations across the country. Eliminates site coefficients and introduces new site designations, which allow uniform hazard spectra and amplified hazard curves to be determined directly based on average shear wave velocity. it also adds new performance requirements for post-disaster and High Importance Category buildings.

Structural Design (Part 9) – Lateral Loads

In response to an increase in the seismic hazard values for many locations in Canada, it updates the seismic design parameter from Sa(0.2) to Smax, adds new prescriptive wood-frame wall types, and extends requirements for bracing to resist lateral loads to locations with low seismic and wind loads.

National Fire Code of Canada

Large Farm Buildings (Parts 2 and 4)

This introduces technical requirements for large farm buildings that address the inspection of mechanical and electrical equipment, the control of flammable gases and vapours, and the storage of flammable and combustible liquids.

National Energy Code of Canada for Buildings (NECB) and NBC Section 9.36

Building Envelope (NECB Part 3)

This updates the air leakage requirements in the prescriptive path to include airtightness testing (which is optional in the performance path). It reduces the allowable fenestration and door areas, and lowers the overall thermal transmittance values for opaque building assemblies and fenestration.

Lighting (NECB Part 4)

This updates the lighting power density (LPD) values to better align them with the efficacy of lighting products available in the North American market. Further, it outlines the lighting power allowances to be used for exterior applications that are not covered by existing provisions.

HVAC and Service Water Heating (NECB Parts 5 and 6, and NBC Section 9.36)

This deletes the NECB trade-off paths for HVAC and service water heating because they are complex and not used by the industry. It updates the performance requirements for HVAC and service water heating equipment in the NECB and Section 9.36 by adding new equipment types and by aligning the requirements with federal energy efficiency regulations and relevant standards.

Tiered Performance Requirements (NECB)

This introduces a new Part to Division B of the NECB that establishes a compliance path with four tiers, each successive tier being increasingly stringent in terms of building energy consumption.

Tiered Performance Requirements (NBC Section 9.36)

This introduces a new Subsection that establishes tiered performance requirements by defining five tiers in terms of overall energy performance improvement, improvement in building envelope performance, and airtightness level. To supplement this tiered approach, it adds new Subsections on prescriptive requirements for compliance with Tier 2 and on airtightness measurement.

Alignment with EnerGuide System (NBC Section 9.36)

This aligns NBC Subsection 9.36.5 with the EnerGuide Rating System to establish this system as an acceptable compliance path.