General information
Problem
Scope and Application of Part 10
The National Building Code of Canada (NBC) applies to the alteration of existing buildings, but relaxations to Code requirements may be granted by authorities having jurisdiction. The different relaxations between jurisdictions leads to inconsistencies in the level of performance of buildings with alterations and creates confusion about the degree of work necessary for the alteration to meet the Code requirements. The requirements applying to the alteration of existing buildings should be clearly stated in a new Part 10 in the NBC.
The scope of the initial version of Part 10 is limited to requirements applying to the alteration of existing buildings that improve the energy performance of the building. Energy performance requirements applying to the alteration of Part 9 buildings (to which Section 9.36. applies) are located in Part 10. Energy performance requirements applying to the alteration of Part 3 buildings will be located in Part 11 of the National Energy Code of Canada for Buildings. The proposed NBC Part 10 must clearly direct Code users where to find the requirements applying to the alteration of the existing building in question.
Application of the Requirements of Part 10 to Extensions
Extensions to buildings (including additions) create a combination of an existing portion of the building and a newly constructed portion. New construction should meet the requirements of the Code, but additional consideration may be necessary for the existing portion of the extended building as a result of the extension. The requirements that apply to the existing building must be clearly stated to avoid confusion in the case of an extension.
Justification
The voluntary alteration of an existing building represents an opportunity to upgrade the building’s safety, accessibility, durability or energy performance. When significant repairs or alterations need to be made is the ideal time to consider upgrading the building’s performance where it is cost-effective to do so, thereby minimizing the incremental cost of the upgrade.
To address the alteration of existing buildings, a guiding principle of the development of provisions is that the provisions should be reasonable, pragmatic and avoid placing an undue burden on building owners. Providing exemptions from or relaxations of the Code requirements that are not practical to apply to an existing building, and that do not lead to a decrease in building performance, allows the flexibility to continue using existing functional materials or equipment by extending their service life and deferring replacement costs.
Code users would benefit from a clarification of the requirements that apply to extensions (including additions) and the alteration of existing buildings, as well as a clarification of the applicable permitted relaxations to Code requirements.
PROPOSED CHANGE
NBC20 Div.B 10 (first printing)
[10.] 10 Alteration of Existing Buildings
[10.1.] -- General
[10.1.1.] -- Application and Definitions
[10.1.1.1.] --- Scope
[10.1.1.2.] --- Application
[10.1.1.3.] --- Compliance
[10.1.1.4.] --- Defined Words
[10.1.1.5.] --- Performance
[10.1.1.6.] --- Extensions
Note A-10.1.1.1.(1) Extent of the Alteration.
- sealing ducts that are accessible,
- insulating piping that is being replaced,
- installing automatic temperature controls on service water heating systems with storage tanks,
- improving impacted or exposed portions of an air barrier system, and
- improving the thermal resistance of exposed wall framing, ceilings or floors.
- to maintain or increase the overall building performance level,
- to avoid negative or unintended consequences and unrealistic expectations,
- to ensure that the building is left in a safe state during the alteration, and
- to encourage alterations without placing an undue burden on building owners.
[10.2.] -- Reserved
[10.3.] -- Reserved
[10.4.] -- Reserved
[10.5.] -- Reserved
[10.6.] -- Reserved
[10.7.] -- Reserved
[10.8.] -- Reserved
[10.9.] -- Energy Efficiency of Housing and Small Buildings
[10.9.1.] -- General
[10.9.1.1.] --- Reserved
[10.9.2.] -- Energy Efficiency
[10.9.2.1.] --- Definitions
[10.9.2.2.] --- Replacement Work
General information
Impact analysis
It is expected that the proposed Part 10 requirements which apply to the alteration of existing buildings would provide a benefit to both the industry and authorities having jurisdiction by providing a consistent set of provisions to ensure an acceptable level of safety and building performance, and to remove ambiguity with respect to the degree of work required to improve performance in the unaltered portion of the building.
Providing exemptions for maintenance, repair or replacement with a similar component where appropriate would permit extension of the service life of materials and equipment, defer system replacement costs and improve building performance without creating an undue burden on building owners.
This proposed change would help reduce the administrative and enforcement costs of assessing the degree to which any particular requirement could be relaxed without affecting the level of performance of the building with respect to the Code objectives.
Enforcement implications
It is expected that a consistent set of provisions that apply to the alteration of existing buildings would help reduce the administrative and enforcement work of assessing the degree to which any particular requirement could be relaxed without affecting the level of performance of the building with respect to the Code objectives.
The proposed changes would aid enforcement by identifying the work necessary to improve energy performance in the unaltered portion of the building.
Who is affected
Designers, engineers, architects, building officials, manufacturers, suppliers and energy advisors.
OBJECTIVE-BASED ANALYSIS OF NEW OR CHANGED PROVISIONS
NBC20 Div.B 10 (first printing)
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