Codes Canada - frequently asked questions


What are Codes Canada publications?

Codes Canada publishes five national model codes, in English and in French: the National Building Code of Canada (NBC), National Fire Code of Canada (NFC), National Plumbing Code of Canada (NPC) and National Energy Code of Canada for Buildings (NECB). They also include the National Farm Building Code (last published in 1995).

The Codes are developed and maintained by the Canadian Commission on Building and Fire Codes (CCBFC), an independent committee of volunteers established by the National Research Council of Canada (NRC). They are published by NRC as models for provincial and territorial building and fire regulations and must be adopted by an authority having jurisdiction to come into effect. In some cases, they are amended and/or supplemented to suit regional needs, and then published as provincial Codes.

How are the Codes developed and updated?

The Canadian Commission on Building and Fire Codes is responsible for developing and updating Codes Canada publications. It is assisted by nine standing committees and several task groups and working groups comprised of hundreds of volunteer members. The Codes are developed and updated using an extensive consensus-based process involving all sectors of the construction community and the public. This code development process benefits from the research, technical and administrative support of the NRC. Ongoing development and updating of Codes Canada publications is necessary so future editions can reflect improvements in technology, address emerging health and safety issues and generally continue to meet the evolving needs of the construction industry and Canadian society.

How do I receive updates?

The Canadian Commission on Building and Fire Codes is responsible for developing and updating Codes Canada publications. If you ordered your publication directly from NRC, you will receive email notification regarding any revisions and errata to the Codes. If you did not purchase your publication from NRC, please register at NRC Virtual Store so that we can notify you. To obtain free access to the revisions and errata packages, contact the NRC Construction Research Centre, Publication Sales at

Have all the national model codes been updated?

The NBC, NFC, NPC and NECB have been updated.

The Model National Energy Code for Houses, last published in 1997, will no longer be published separately. Its provisions dealing with energy efficiency for housing and small buildings have been incorporated into a new section of Part 9 of the NBC, Section 9.36.

With respect to the National Farm Building Code, last published in 1995, a Joint Task Group of the CCBFC and the Provincial/Territorial Policy Advisory Committee on Codes will examine farm building requirements this code cycle (2020). The fire and structural requirements in the National Farm Building Code are increasingly in conflict with the latest edition the National Building Code.

Have the intent statements been updated for the 2015 Codes?

The intent statements pertaining to the 2015 Codes are available, free of charge on the Codes Canada website. The application statements for the 2010 Codes have not been updated as the CCBFC has discontinued their publication.

How different are the 2015 Codes from the 2010 editions?

Since the 2010 editions of the NBC, NFC and NPC, nearly 600 technical changes have been incorporated in the 2015 editions to address technological advances, social policy and health and safety concerns. Examples of new areas can be found in the introduction of water use efficiency in the NPC and the expansion to six-story combustible construction in the NBC and NFC. A summary of the significant changes to these Codes is available on the Codes Canada website.

Will revisions to Codes Canada publications be published after they are released? If so how do I get the revisions?

Revisions and errata approved by the CCBFC are published in mid-cycle, while emergency changes are released immediately. Revisions to Codes Canada publications are available on request. Please contact Publication Sales at for revisions and errata access.

When will the next version of the Codes be released?

New editions of the four major codes (National Building Code, National Fire Code, National Plumbing Code, and National Energy Code for Buildings) are published every five years, with the current code cycle running from 2015 – when the last edition was released – to 2020. The 2020 codes were expected to be published in early 2021, however publication has been postponed due to a number of factors, including: the complexity of the proposed changes; a significant volume of comments received from the public review; the COVID-19 pandemic, and at the request of provinces and territories to receive all codes documents at the same time. The 2020 editions of the national model codes are now anticipated to be published in December 2021.

If I find something wrong with the Codes that needs to be changed, who do I tell and what do I do? OR I would like to make a change to the Codes. How do I forward this change and who do I forward it to?

Any code user can submit technical inquiries or request a change to the national code documents. Information on how to do this can be found on the Codes Canada website under Technical enquiries and Request a code change.

Free access to electronic Codes

Why are the Codes free now after all these years?

In the 2018 Fall Economic Statement, the Government of Canada announced funding that will support ongoing and future code development work. The goal of this initiative is to reduce barriers to trade and encourage provinces and territories to align building codes across the country. As part of this, electronic access to the National Building, Fire, Plumbing and Energy Code for buildings was made be freely accessible on the NRC's website as of April, 2019.

Are all Codes Canada publications free?

The electronic editions of the National Building, Fire, Plumbing and Energy Code for buildings are free. That includes access to the downloadable, offline access PDF file and the single user, online access subscription. Printed versions of these Codes, as well as electronic and printed versions of Codes Canada's Guides, are available for purchase at a reduced price.

Can I get a refund on the Code I already purchased?

No, NRC will not be refunding purchases. As soon as the funding was confirmed, a notice about the upcoming changes was posted on the NRC website, including each Code product page, and on Virtual Store. The funding and the price changes are effective as of April, 2019.

Why is it that the price for the printed version is now the same for the older codes and the most recent codes? Should the latest codes not have more value?

The price of the printed version of the Codes is now based on cost recovery. The price reflects the operating cost to print, bind and package the Code for shipping. Although the Codes develop and evolve to keep pace with industry change, the volume of the publications has remained relatively constant over the last three Code cycles.

Why are the Guides not free?

The Guides are supporting documents, and do not become legislation as do the Codes. They are available at a reduced price to encourage their use and accessibility to the industry.

Why did the NRC charge for the Codes in the past?

The information the Codes contain is developed at great expense (e.g. participation of hundreds of experts in committee meetings, research and studies, administrative and technical support) which was, until April 2019, funded in large part from the sale of the Code documents (either in hard copy or electronic versions) and by NRC.

Accessing electronic Codes

Why is there a delay from the time I place my order until I can access my Code product?

There is a delay of one business day before the order can be processed and activated because it involves a manual process of uploading batched orders into a database before an order can be activated. Codes Canada is working on a solution to simplify the process and reduce or remove the delay.

Will the 2020 editions be available without having to go through all of these steps?

Yes, the 2020 editions of Codes Canada publications will be available online in Web-accessible HTML format, according to Treasury Board's Standard on Web accessibility, following their publication in PDF format. They will also be available in paper format.

Are the Codes mobile friendly and Web accessible?

Codes Canada's downloadable and online formats are currently not supported on mobile devices. Gilmore Global's eVantage platform offers a mobile-friendly eBook. Following their publication in PDF format, the 2020 editions of Codes Canada publications will be made available in a Web-accessible HTML format, that will meet the Treasury Board's Standard on Web accessibility, will be mobile-friendly and will respect internationally accepted guidelines for Web accessibility.

I am visually impaired and cannot read the PDF online. How can I access the information?

Codes Canada publications are available in PDF format and can be accessed through text-to-speech software such as Adobe Read Out Loud. If you wish to obtain accessible copies or other accommodations please Contact Codes Canada (Email:


How do I order the Codes?

Code publications produced by Codes Canada are available free in electronic format and for purchase in printed format. User's Guides now have a reduced rate for both formats.

To access both the free products and those available for purchase, place your order on-line by selecting your products through the NRC Virtual Store. Alternatively, you can send a completed order form (PDF, 500 KB) to Codes Canada Publication Sales by fax, e-mail or regular mail.

More details can be found on the Codes Canada Publications Web page. If you wish to reach us, our office is open from Monday to Friday, 8:30 am to 4:30 pm, eastern time, at 1 800-672-7990 or 1-613-993-2463 (Ottawa-Gatineau and outside of Canada) or by email at


Will the delivery of the Codes be faster if I order them through the NRC Virtual Store?

No. All orders are processed in the order they are submitted. Codes are usually delivered within 2 weeks. However, if they are out of stock, it could take 4-6 weeks for delivery.

The National Building Code is sold in two volumes. Can I purchase only Volume 1?

No, the volumes are not sold separately. The reason is that both volumes are required to understand and use the Codes' requirements. Please note that the distribution of code material in each volume is different than in the previous editions The NBC 2015 has been re-organized to consolidate relevant information. Each Part now contains the Prescriptive Requirements, followed by the related (appendix) Notes. Parts 1 to 8 are found in Volume 1 and Part 9 now forms Volume 2

Can I get a discount if I purchase more than one product?

There are several discounts available; however, discounts cannot be combined. Please note: Only one (1) discount from the list below can be applied to an order. The highest discount will be applied.

  • Bulk orders discount: 10% discount on minimum order of 10 copies of same printed document (same title and format).
  • Student Discounts: 25% discount when proof of student ID is provided to Pub Sales. A scanned copy sent by fax or email is sufficient.
  • Educational bookstore discount: 25% discount on minimum order of 10 printed documents. The client must have an existing educational bookstores account created with NRC to be eligible. In order to be eligible for the discount, the bookstore must be located on campus. To apply, please send a request to
  • Concurrent Users discount: The volume discounts apply to subscriptions for concurrent users and is based on number of users who purchase the same title.
    5- 9 Users = 20% 25 – 49 Users = 40%
    10 – 24 Users = 30% 50+ Users = 50%
The Codes are available in printed formats. Can they also be viewed online on the Web?

Codes Canada publications are available as online access subscriptions and downloadable, offline access documents (single user only). There are several types of subscription available depending on the edition. The online subscriptions are offered for single and concurrent users. Visit the NRC Virtual Store for more information.

Are User's Guides available? If not, when will they be available?

Two new User's Guides were published in 2017: the User's Guide – NBC 2015, Structural Commentaries (Part 4 of Division B) and the Illustrated User's Guide – NBC 2015 Part 9 Housing and Small Buildings. A third guide, the User's Guide – National Energy Code of Canada for Buildings 2015 is expected to be released in 2019.


Are the Codes mandatory?

Codes Canada publications are model documents only and must be adopted by an authority having jurisdiction in order to come into effect, as Canada's constitution gives the ten provinces and three territories jurisdiction over construction. In some cases, they are amended and/or supplemented to suit regional needs, and then published as provincial Codes. It is anticipated that the most recent editions will form the basis of provincial and territorial regulations in the near future. To find out about Code adoption in your jurisdiction, please contact the appropriate government agency listed on the Codes Canada website under Provincial or territorial ministries.

Are the Codes a guide on how to construct a good building?

The Codes are not a design guide or a "how-to" book on how a house or building should be built. Rather, when adopted by a provincial or territorial jurisdiction, they set out minimum requirements for building construction. Best practices will often exceed these minimum provisions.

Will I have to update my house or building now that the new Codes have been released?

No. The new Codes are model Codes that apply to new construction and major renovations to existing buildings, as well as additions in some jurisdictions. They must be adopted by a provincial or territorial jurisdiction to take effect. Some regulatory authorities may require that some provisions of the new Codes apply to existing buildings. To find out about the application of the Codes in your jurisdiction, please contact the appropriate government agency listed on the Codes Canada website under Provincial or territorial ministries.

Do I have to follow the new national Codes as soon as they are released?

No. To come into effect, the national model Codes must be adopted by a regulatory authority. There may be a period of a few months or years before a province or territory adopts the new Codes. Information about model code adoption across Canada is available on the Codes Canada website. To find out about adoption plans in your jurisdiction, please contact the appropriate government agency listed on the Codes Canada website under Provincial or territorial ministries.

If I'm regulated by my province, do the Codes apply to me?

It depends on the specific province or territory you are in. Information about model code adoption across Canada is available on the Codes Canada website. To find out about adoption plans in your jurisdiction, please contact the appropriate government agency listed on the Codes Canada website under Provincial or territorial ministries.

As a general guide only, Codes Canada publications are normally adopted by reference by Manitoba, New Brunswick, Newfoundland Labrador, Nova Scotia, Nunavut, North West Territories, Saskatchewan, and the Yukon Territory ("adoption by reference" means that a public authority includes a reference to a model code in their laws, ordinances, regulations, or other legal instruments, turning the model code into law).

Codes Canada publications form the basis of the provincial Codes in Alberta, British Columbia, Ontario and Quebec. Prince Edward Island does not currently adopt the national model provincially, but the cities of Summerside and Charlottetown have, through bylaws, adopted the NBC and NFC.

Federal government buildings and buildings associated with federally regulated industries (such as airports) are required to conform to the national model as well as applicable provincial or territorial regulations.

I live in Ontario, and will be purchasing the Ontario Building Code. Should I also order the national Codes?

If you are planning on doing work for the federal government, you will need Codes Canada publications. Many people also order the Codes when the projects they are working on involve different provinces.

Scope of construction codes

What is the extent of Canada's national model codes development system? How many people are involved?

Canada's national model codes development system involves more than 440 volunteers from across Canada who fill about 1130 active committee member positions on over 90 committees. These volunteers, who are evenly split between three broad interest categories (regulatory, industry and general interest), generally serve on three committees each. For each five-year code cycle, the in-kind value that they contribute, assuming an average of three full-day meetings per year, is close to $20 million. The CCBFC itself has 27 voting and 17 non-voting members and meets in person at least once annually. Its nine Standing Committees, which average 23 members each, meet twice a year. These in-person meetings rotate to locations across Canada to encourage public attendance and the participation of code users. The CCBFC Executive Committee, which directs business on behalf of the CCBFC, meets as often as needed, often by teleconference. The multitude of task groups and working groups created to address specific issues also meet by teleconference. In sum, about 20 in-person meetings, and over 300 teleconference meetings, are held each year.

In the current code cycle, CCBFC committees are addressing more than 120 approved tasks from the several hundred specific Code Change Requests submitted to the Commission over the last few years. These tasks span a broad range of topics and address new technologies (i.e. insulated concrete forms; exterior insulation and finish systems) as well as safety issues (i.e. asbestos, accessibility in residential units) and national priorities (i.e. higher energy performance requirements in building codes). Proposed changes are submitted for public review each fall. The number of proposed changes ranges widely from year to year, with some years having only 30-50 while others have more than 200. The 2013 public review, for instance, had 361 proposed changes posted for comment. Every proposed changes includes extensive documentation, from the original request through the analysis and proposal-development stage, the review of public comments and, finally, the CCBFC's decision on whether or not to approve the change.

New editions of the four major codes (National Building Code, National Fire Code, National Plumbing Code, and National Energy Code for Buildings) are published every five years. The fifth in the series, the National Farm Building Code, was last published in 1995 and is currently under review. In between editions, several technical guides are published to supplement the Codes. Revisions and errata approved by the CCBFC are published in mid-cycle, while emergency changes are released immediately. Several provincial versions of the national codes are also published, through licensing agreements with these jurisdictional authorities.

Who is responsible for regulating construction in Canada? Who provides Code interpretations?

In Canada, it is the provincial or territorial governments that have the authority to enact laws and regulations pertaining to buildings and facilities. Some cities also have this authority through a special relationship with their provincial authority.

The CCBFC develops and updates Codes Canada publications (National Building Code, National Fire Code, National Plumbing Code, National Energy Code for Buildings, and National Farm Building Code), which are adopted with or without modification and enforced by most provinces and territories. Typically, these jurisdictional authorities delegate responsibility for enforcement to the building, plumbing and fire officials employed in local municipalities. Provincial and territorial authorities having jurisdiction are also responsible for interpreting the codes, providing training and education, issuing permits, conducting inspections, and establishing the roles and responsibilities of trades people and professionals. Individuals seeking a technical opinion on the intent of a requirement in adopted codes should therefore approach the appropriate municipal, provincial or territorial official.

For more information, see Canada's national model codes development system.

Who establishes the content of the codes?

The CCBFC is responsible for developing and updating the Codes Canada publications. It oversees the work of technical committees, and several task groups, who propose the content of the model codes based on input from its stakeholder community. Committee members are selected from industry, the regulatory community and general interest groups, as well as all relevant sectors and geographical areas of the country, to ensure balanced representation. Changes to the Codes proposed by the committees must be approved by the CCBFC before publication by NRC.

What do Codes Canada publications address? What do they not address? Why?

Codes Canada publications set out minimum requirements addressing safety, health, accessibility, building protection, and energy efficiency. Four of the codes (National Building Code, National Plumbing Code, National Farm Building Code, and National Energy Code for Buildings) apply to the design and construction of new buildings and additions. Except for the National Energy Code, these also apply to change of use or substantial renovation of existing buildings. The National Fire Code applies to buildings and facilities already in use and regulates activities that create fire hazards.

The Codes do not address whether a building is aesthetically pleasing or durable since these fall outside the scope of their stated objectives (i.e. safety, health, accessibility, building protection, and energy efficiency). Characteristics of buildings and facilities that might be considered to have a bearing on code objectives, such as addressing psychological health or protection from vandalism, also fall outside the Codes' stated objectives.

The Codes are not textbooks on building design and construction, or maintenance and operation. They do not list proprietary building products or address situations that arise only rarely. They also do not address administrative issues, such as professional qualifications or compliance certifications, as that could result in conflict with related provincial/territorial legislation and regulations. Lastly, their limited scope means that they have little, if any, application to what is traditionally thought of as "consumer protection"; buyers are considered responsible for protecting their own interests.
For more information, see Guidelines for requesting changes.

Roles and responsibilities

What is the role of the Canadian Commission on Building and Fire Codes?

The Canadian Commission on Building and Fire Codes (CCBFC) is an independent committee of volunteers established by the National Research Council of Canada (NRC) to provide direction and oversight on the development of Codes Canada publications. The CCBFC oversees the work of several standing committees, special purpose committees, and task groups involving more than 400 volunteers chosen from across the country for their individual interests and expertise. Its nine standing committees are responsible for developing and improving the technical content of the codes and related documents, such as user's guides, thereby helping to protect the health and safety of Canadians. The CCBFC works in partnership with provincial and territorial regulatory authorities to promote uniform adoption and understanding of the model codes by responding to their needs and priorities and facilitating the resolution of issues.

Who serves on the CCBFC and how are they selected?

The CCBFC is made up of voting and non-voting members from across Canada. These members are appointed by NRC. Voting members, non-voting major partner members, the Vice-Chair and the CCBFC Chair are appointed on the recommendation of the CCBFC Selection Committee.

Voting members (numbering at least 27, including the Chair) are volunteers who represent, in a balanced way, regulatory authorities, general public interests and industry from all regions of Canada.

Major partner non-voting members comprise representatives of the Canadian Steel Construction Council, the Canadian Wood Council, the Cement Association of Canada, NRCan, and a standards development organization accredited by the Standards Council of Canada. There are also two ex officio non-voting liaison partners (the Chairs of the Provincial/Territorial Policy Advisory Committee on Codes and the Canadian Commission on Construction Materials Evaluation). The other ex officio non-voting members comprise Standing Committee Chairs, the Deputy Chair (Managers, NRC Codes Canada), NRC Construction Policy Advisor (Director, NRC Building Regulations),and Secretary (NRC Construction staff member).

More information is available in the Policies and Procedures – CCBFC document.

More information is available in the CCBFC Policies and Procedures document, which is available on request.

Given that the CCBFC has, in its membership, regulatory officials from provincial and territorial governments, how are their roles and responsibilities defined? Do they participate as individuals or as representatives of their respective governments?

The roles and responsibilities of members of the CCBFC and its committees are the same for all categories of members. CCBFC members are expected to be broadly knowledgeable on Code-related matters and able to exercise objective judgments as well as independent decisions regarding CCBFC business. Members do not serve as proponents of any particular employer or group and do not provide preferential treatment to anyone in any official manner. Members are expected to act honestly and in good faith. They are also expected to use confidential information only for the purposes of the CCBFC.
Conditions of serving on the CCBFC or its committees are described in more detail in the Policies and Procedures – CCBFC document, which is available on request.

What is the role and mandate of the provinces and territories?

Canada's constitution gives the provinces and territories jurisdiction over construction, making them key partners in Codes Canada's development system. Some cities also have this authority through a special relationship with their provincial authority. As a result, provincial and territorial authorities having jurisdiction are responsible for adopting and enforcing laws and regulations, providing interpretation of these laws and regulations, providing training and education, and establishing roles and responsibilities of trades people and professionals.

What is the role and mandate of the Provincial/Territorial Policy Advisory Committee on Codes (PTPACC)? To whom is it accountable for its policy advice?

The Provincial/Territorial Policy Advisory Committee on Codes (PTPACC) is a committee made up of senior representatives appointed by provincial and territorial deputy ministers that provides policy advice to the Canadian Commission on Building and Fire Codes. This forum gives the provinces and territories the opportunity to provide guidance on the scope, content, format, and development process of the Codes.

Is there a formal agreement among governments which sets out the role and purpose of Codes Canada Publications, and the commitments and expectations of provincial and territorial governments in relation to them?

Yes. There are formal agreements between the various levels governments that set out roles and responsibilities, as well as commitments and expectations, with respect to Codes Canada publications. They include provisions for producing, selling and adopting the Codes. These agreements, however, are between governments and are therefore not public.

Does the CCBFC provide advice to provincial governments when the latter are considering changes to their building codes? If so, how is this done?

The officially released Codes Canada publications represent the sole advice of the CCBFC. The CCBFC does not provide other advice, but the Commission does maintain an ongoing dialog with the Provincial/Territorial Policy Advisory Committee on Codes (PTPACC), and both parties sit in on each other's meetings. Through that dialog, the CCBFC is informed of code changes that the provinces and territories are contemplating, and vice versa.

If a province or territory determines that a national code change is either acceptable or unacceptable, how does this affect the decision of the CCBFC? Can objections from a province or territory prevent the CCBFC from adopting a proposed code change?

The process for determining if a code change is accepted depends on the situation and can vary considerably. The provinces and territories are consulted and provide input on proposed code changes. If a large majority of jurisdictions support a proposed change, it normally proceeds through all considerations. If, from an administrative or policy point of view, some jurisdictions are concerned about a proposal that has received support through public review, the CCBFC will try to further address the concerns through an ad hoc committee. The committee will attempt to find a solution that may procure a greater consensus. Consensus, however, does not imply unanimity. If a strong consensus is not possible, the proposal will normally be withdrawn so as not to create disharmony. If the concern relates to a technical issue, the proposal has a good chance of surviving but may be revised to address the concern.

What is the role of NRC?

NRC establishes the Canadian Commission on Building and Fire Codes (CCBFC), an independent committee of volunteers responsible for developing and maintaining the national model codes, based on broad consultation and consensus principles. Through NRC Construction, NRC provides technical, research and administrative support to the CCBFC and its committees. It publishes Codes Canada publications on behalf of the Commission, as well as some of the provincial codes based on the national models on behalf of the jurisdictions.

NRC staff serving on CCBFC committees have no voting privilege. NRC does not control what goes into the national model codes or the provincial/territorial codes based on those models, as it is the provinces and territories that have jurisdiction over construction in Canada.

Making code changes

How does a person propose a code change? What is involved, and do you need to be an "expert" to do this?

Suggestions for changes to Codes Canada publications are welcome from anyone at any time. A specific Code Change Request form is available online to formulate and submit a request. It is not necessary to be an "expert". Anyone submitting a Code Change Request should ensure that it is clear and focuses on technical issues that are generic or widespread. The request should include:

  • the existing Code requirement, if applicable
  • the reasons for the change or addition
  • the proposed revision or new requirement
  • supporting documentation, including cost/benefit data
  • the enforcement implications, and
  • the related Code objectives.

Requests that do not satisfy these criteria will be returned to proponents for additional information. For more information, see Guidelines for requesting changes.

When a code change is being considered, what information and factors are taken into account? What factors are not considered? Why?

In looking at each proposal, the Canadian Commission on Building and Fire Codes (CCBFC) seeks answers to the following questions:

  • What is the problem that the proposed change seeks to address?
  • What is the proposed solution and how does it address the problem?
  • Which of the stated objectives and functional statements of the Code will the proposed solution assist in achieving?
  • What are the cost/benefit implications?
  • What are the enforcement implications?

Factors not taken into account include aesthetics, comfort, workmanship, maintenance and life-cycle costs, and anything that cannot be related to a specific objective, is not enforceable, or is above minimum requirements. Some characteristics of a building that could be perceived as having a bearing on Code objectives, such as psychological health or protection from vandalism, are also not addressed.

I understand that I can provide input to the CCBFC, but my building code is managed by my province. Can I also discuss code issues with my provincial government? If so, who do I talk to?

Yes. The CCBFC is responsible for developing and updating Codes Canada publications but it is the provinces and territories that have jurisdiction over construction. Most provinces and territories adopt these model codes, sometimes amending and/or supplementing them to suit regional needs before publishing them as provincial codes. To talk with someone in your local jurisdiction about code issues, visit the provincial or territorial ministries page for the relevant contact information.

Can the code development process respond quickly to emerging issues, or must everything wait until the end of each five-year cycle? Does it take long to make changes to the Codes?

Emerging issues are dealt with through the regular code development cycle. It may take a few months, or several years, to develop and secure approval for a proposal that is then adopted in the next edition of the Codes, depending on the complexity or scope of the matter. If it is an emergency issue that affects life safety or has a major impact on industry, the CCBFC responds immediately and issues an interim change.

What is the "consensus-based decision-making process" that is used to update and produce the Codes and how does it work? Why is it important?

Consensus is the substantial agreement of members and includes the resolution of all significant concerns and technical disagreements. It implies much more than the concept of a simple majority, but it does not necessarily imply unanimity. Consensus requires that all opinions be considered and weighed and that any statement of committee agreement should be reached only after full and fair discussion of the issues involved. When consensus on a proposed change has not been achieved, additional development is undertaken, or the proposed change is rejected and the proponent of the requested change is informed. Committee decisions are based on this principle, whenever possible.

Why do the Codes only set minimum standards of health and safety? What is meant by "minimum requirements"?

In a world of limited resources and competitive markets, it is important that building infrastructure be provided in a cost-effective manner. On the other hand, regulators need building codes that establish realistic minimum acceptable standards to ensure safety and meet other objectives such as health, accessibility, building protection, and energy efficiency.

The national model Codes are not best practice guides. By specifying particular minimum solutions acceptable to society at the time, they establish a level playing field that everyone can build to, cost-effectively. Many owners, designers and builders seek to achieve a higher standard than specified in the Codes, which is perfectly legitimate. By identifying the base line, the Codes provide a starting point that has broad agreement.


Is training offered on the technical changes to the Codes?

Codes Canada Seminars:

To help code users understand the new code provisions and their impacts, the National Research Council of Canada offers a variety of products to engage and inform stakeholders on the significant technical changes in the 2015 Codes. These information products include on-site seminars, handbooks, online presentations and workshops.

What training programs are there to educate users on the content of the Codes?

Training and education in Canada is a provincial/territorial responsibility. With regards to building and fire Codes, such training is normally provided by community colleges, universities, consultants, associations and other agencies. To find out about Code training programs in your jurisdiction, please contact the appropriate government agency listed on the Codes Canada website under Provincial or territorial ministries.

Objective-based Codes

What is an objective-based Code?

An objective-based Code includes objectives or goals that the Code is meant to achieve. In an objective-based Code, every technical requirement achieves one or more of that Code's stated objectives (e.g. Safety, Health, Accessibility, Fire and Structural Protection of Buildings, Environment). Applying the provisions in the Codes is one option for compliance, since they meet one or more of the Code's stated objectives by default. The other option is the use of alternative solutions. These must achieve at least the same level of performance and satisfy the same objective(s) assigned to the associated Code provisions.

When did objective-based Codes come into effect?

The National Building, Fire and Plumbing Codes were first published in objective-based form in 2005, following extensive consultation with the provinces and territories. The National Energy Code for Buildings was first published in objective-based form in 2011. Subsequent editions of the Codes all follow the same approach.

Aren't objective-based Codes just performance-based Codes?

No, they are not. Although the Codes have some performance requirements, and there is an ongoing evolution toward adding more of them, they will remain mostly prescriptive for many more years.

Are objective-based Codes part of Smart Regulation?

Yes, they are. Objective-based Codes are Codes with all of the "whys" spelled out, so that code users know exactly what is important and why. This should facilitate the development of alternative solutions that meet minimum Code requirements. The additional information should also increase understanding of Code requirements and facilitate conformance assessment.

Can a requirement be added to the Codes that is not related to one of the stated objectives?

The simple answer is "no". In an objective-based Code, every requirement is related to at least one of that code's stated objectives.

Of course the existing objectives of Codes Canada publications are not necessarily frozen for all time. Other objectives may be added and one or more of the existing objectives could be dropped. However, this would constitute a major change and would only happen if extensive consultation with the provinces and territories and other stakeholders indicates a broad consensus that such an expansion or contraction of the Codes' scope should occur. For example, this process took place in the 2015 Code cycle with the development of water use efficiency requirements and objectives.

Energy efficiency

How do the Codes address climate change?

The national code documents do not directly address issues related to climate change mitigation. However, the climatic data that forms the basis for much of the design of buildings is continuously being updated in the National Building Code of Canada to ensure it is current. It is anticipated that adoption of the energy efficiency requirements in the National Energy Code of Canada for Buildings and in Part 9 (housing and small buildings) of the National Building Code of Canada will contribute to a reduction in greenhouse gas emissions.

How do the Codes address energy efficiency?

The National Energy Code for Buildings directly addresses the use of energy as it relates to resource conservation under a new objective called "Environment". The same Environment objective was incorporated in the NBC and provisions dealing with energy efficiency for housing and small buildings are found in Section 9.36. of the NBC.

How do the Codes address resource conservation?

The new Environment objective in Codes Canada publications has a "Resources" sub-objective that, so far, addresses excessive use of energy and excessive use of water. It may be expanded in the future. This would only happen if extensive consultation with the provinces and territories and other stakeholders provides a broad consensus that such an expansion should occur.

Where can I find additional reading on the long-term strategy for energy code development?

CCBFC Position Paper on a Long-Term Strategy for Developing and Implementing More Ambitious Energy Codes, September 14, 2016 Chapter on 'Built Environment' in the 'Complementary actions to reduce emissions' of the Government of Canada's Pan-Canadian Framework on Clean Growth and Climate Change, December 14, 2016

Energy efficiency – buildings

What is the National Energy Code of Canada for Buildings?

The National Energy Code of Canada for Buildings (NECB) is one of several model codes published by the National Research Council of Canada (NRC). The NECB replaces the Model National Energy Code of Canada for Buildings 1997 (MNECB). As with other Codes, it was developed by the Canadian Commission on Building and Fire Codes (CCBFC), an independent committee of volunteers established by NRC, and published by NRC. The NECB is a model for provincial and territorial regulations and must be adopted by an authority having jurisdiction to come into effect. In some cases, it may be amended and/or supplemented to suit regional needs, and then published as a provincial Code.

How was the NECB developed?

The NECB is the result of an extensive consultation process involving stakeholders from multiple levels of government (federal, provincial, territorial and municipal), the construction industry, and the general public. It was developed by the CCBFC, with technical support and funding provided by NRC and Natural Resources Canada (NRCan) as part of its commitment to improving the energy efficiency of Canadian buildings and reducing greenhouse gas emissions.

What's new in the 2017 NECB?

The NECB 2017 reduces the overall thermal transmittance of roofs, fenestration and doors; reduces losses through thermal bridging in building assemblies; and, reduces the allowable percentage of skylight area. This new edition also introduces more stringent requirements for energy recovery systems and interior and exterior lighting requirements. It requires temperature controls in individual guest rooms in hotels and motels and demand control ventilation systems in commercial kitchens. In Part 4, it clarifies the lighting trade-off path requirements and in Part 8, it makes performance compliance requirements consistent with prescriptive requirements.

What's new in the 2015 NECB?

The 2015 NECB includes over 90 changes improving the overall energy performance of buildings over the 2011 edition. The 2015 edition broadens the scope to address all service water and introduces requirements for pressure-sensing controls which reduce the short-cycling of booster pumps when demand for water is low. Other HVAC and service water changes include equipment efficiency regulation of heat rejection equipment, such as cooling towers and (standalone) condensers, heating performance requirements for gas-fired outdoor packaged units and updated minimum pipe and duct insulation requirements. Lighting power density values and controls have been updated with more stringent lighting allowances and additional requirements for common spaces and exterior applications. The performance path modeling rules and guidance have been updated to reflect the changes to the prescriptive path as well as more current typical use profiles of buildings. Application of the code for residential and small buildings has also been clarified.

Why is there a 2015 and 2017 edition of the NECB?

NRC and NRCan published an interim edition of the NECB in response to proposals received that improve the overall energy performance of buildings over the 2015 edition. Modelling for these changes indicates a potential energy efficiency improvement of between 10.3 and 14.4 % over the NECB 2011. The 2017 edition is an important step toward Canada's goal for new buildings, as presented in the Pan-Canadian Framework, of achieving 'net zero energy ready' buildings by 2030.

What is the scope of the NECB? Is there going to be an energy code for houses as well as for buildings?

The NECB applies to all buildings in Part 3 of the National Building Code of Canada (NBC). There will no longer be a National Energy Code for Houses. Instead, energy efficiency requirements for housing and small buildings are incorporated into Section 9.36 of the NBC.

Energy efficiency – housing

How much better are the NBC's new energy efficiency requirements for housing over the Model National Energy Code of Canada for Houses 1997?

Comparison of average energy consumption, such as was done between the National Energy Code of Canada for Buildings 2011 (NECB) and the Model National Energy Code of Canada for Buildings 1997 (MNECB), was never carried out for the energy efficiency requirements for housing in Part 9 of the National Building Code of Canada 2010 (NBC). The reason was that the Canadian Commission on Building and Fire Codes (CCBFC), with advice from the provinces and territories, defined the target for these requirements as a desired Energuide rating and not as an improvement over previous codes. The fact that the Model National Energy Code of Canada for Houses 1997 (MNECH) had never been used as a mandatory reference also played in this decision.

For the energy validation of the requirements, no baseline was therefore necessary and the validation instead focused on assessing the Energuide rating of eleven archetype houses simulated in six climate zones. The result was a slightly better rating than 78 in the Energuide Rating Scale (ERS), on average, across the six climate zones and the 11 archetype houses. More information is provided in the final validation report, which is available on request.

For the cost/benefit analysis, a current construction baseline was developed based on 2009 data. The construction features that made up the baseline are described in the cost-benefit report, which is available on request.

The incremental cost for each feature (increased insulation, upgraded furnaces, etc.) was assessed, as was the respective energy saving. A whole-house analysis using one of the eleven archetype houses across all six climate zones was also carried out. The result was that the average energy saving from the 2009 baseline to the performance level prescribed by Section 9.36. of the NBC was 10%. CCBFC committees also considered the potential energy savings according to each incremental improvement in the ERS according to Natural Resources Canada (NRCan) data. For example, the energy savings for a typical house that was improved from ERS 72 to ERS 78 was estimated to be 29% of the total energy used by that house. Similarly, the energy savings for a house that was improved from ERS 74 to ERS 78 would be 20% and, for a house improved from ERS 75 to ERS 78, 16%.

The baseline energy performance of the eleven archetype houses was not formally established through simulation as per the Energuide System. It was, however, estimated that the eleven houses would have an approximate average ERS rating of 74 if they were built with the 2009 baseline construction features established by the CCBFC. Their estimated energy efficiency could therefore improve by 20% if the same houses were built according to the prescriptive requirements in Section 9.36.

In summary, it could be said that the savings on the total energy use that may be achieved with the new requirements in Section 9.36. of the NBC are likely between 10% and 20% over that of standard 2009 construction, depending on the type of house (its configuration, volume and architectural features) and the climate zone where the house is located.

Log home construction

Will the energy efficiency requirements eliminate log homes from the Canadian landscape?

No. The Canadian Commission on Building and Fire Codes (CCBFC) was keenly aware of the issues related to energy efficiency in log home construction. From the beginning, the committees working on these changes were concerned that the new energy requirements might eliminate log home construction, and they discussed the matter with the log home construction industry. The president of the BC Log and Timber Building Industry Association also attended a committee meeting, and two consultants working for the log home industry provided technical data to the committees. As a result, the lumber material data and calculation methods for log walls were made consistent with those used by the log home industry.

Why isn't there a simple exemption for log walls?

The requirements address the energy used by the building with no exemption within the prescriptive requirements for any specific type of assembly construction. This approach levels the playing field for energy use by the building, regardless of the type of construction used. Unlike the Model National Energy Code of Canada for Houses 1997, the new requirements therefore do not include a single, specified RSI value for all log walls.

How is the RSI value for log walls calculated?

The requirements include a reference to the thermal envelope section of the ICC 400 standard "Design and Construction of Log Structures". This standard establishes the minimum requirements for log structures to safeguard the public health, safety and welfare through structural, thermal, and settling provisions. The ICC 400 document defines the wall thickness as the "average cross sectional area divided by the stack height".

This approach puts all log profiles on a level playing field regardless of their size or shape. It eliminates any variation, averaging or rounding necessary to determine profile factors for particular log shapes. Once the log wall thickness is established, the RSI‐value for a log wall can be looked up in a table. This table shows the appropriate effective thermal resistance based on wall thickness and on the specific gravity of the appropriate wood species – including the exterior and interior air film coefficients.

Are log walls considered an air barrier system?

Yes. The air permeance of solid lumber is negligible and timber logs can therefore be treated as an air barrier material. To become an air barrier system, log walls must comply with prescriptive requirements for airtightness. This means that the joints between logs need to be designed to receive and maintain the sealants through in-service conditions such as shrinkage and settling. Joints also need to resist air and moisture infiltration and sealant materials must be compatible with all materials in contact with the sealant. Many of these requirements are required in the thermal section of the ICC 400 standard "Design and Construction of Log Structures".

Are log walls considered to have a vapour barrier?

Yes. Solid timber has a low enough vapour permeance so that it meets the NBC requirement of 60 ng/(Pa•s•m2), which technically makes it a vapour barrier. For example, test results indicate that a 2x6 wood stud (SPF) has a vapour permeance between 20 and 30 ng/(Pa•s•m2) depending on the wood's orientation and the testing direction (thickness). Unlike for air barrier systems, there is no NBC requirement that a vapour barrier must be continuous. This requirement is not being added.

Can log homes comply with the prescriptive requirements?

Log homes can comply with most requirements in the prescriptive path. The main issue with log wall construction is that pure log walls generally are not able to meet the required prescriptive RSI-values for above-grade walls – especially in the colder climate zones. In all other prescriptive energy requirement aspects (i.e. roofs; floors; basements; heating, ventilating and air-conditioning equipment efficiency; water heating equipment efficiency), log home construction could be considered roughly equal to conventional construction. Log home builders should therefore be able to comply with the same adjustments that the rest of the industry has to make. There are prescriptive requirements specifically for calculating log wall RSI values and for construction of air barrier systems using log walls.

A trade-off method for walls (including log walls) is available that could help log home builders demonstrate compliance with the requirements. For example, the trade-off method allows the installation of additional attic insulation to make up the difference between the required RSI-value for walls and the actual effective RSI-value achieved by the log construction.

Which log types are affected most in having to use alternative compliance routes?

Some log types, for example large-diameter rectangular logs or hybrid (insulated) log wall construction, would meet the prescriptive requirements in many climate zones. In the Northern climate zones, and for wall construction with thinner or round logs that have lower thermal resistances, a trade-off with additional attic insulation is needed to make up the difference between the required RSI-value for walls and the actual effective RSI-values achieved by the log walls.

Is there a limit to how much insulation can be traded within the trade-off path?

In the simple trade-off method, the RSI-value of walls cannot fall below 55% of the required value. Most, if not all, log wall constructions meet this limit. Other limitations are that only above-grade assemblies can be traded, and opaque assemblies can only be traded against other opaque assemblies (e.g. wall against attics). These limitations are necessary because the differences between how heat is transferred through above-grade and below-grade, or through windows, are significant. The limitations apply to all buildings using the trade-off path.

What if the trade-off method does not allow sufficient flexibility, say in the North?

If the difference between the required and actual log wall R-value is too large to be made up by additional attic insulation, the builder can use the performance path. In the performance path, improved basement or floor insulation, heating and ventilation efficiencies or other energy efficient construction features can be used to trade off the missing resistance in walls. The performance path can be completed through computer simulation using, for example, NRCan's HOT2000 software, which is the same tool used for NRCan's Energuide Program for New Houses. The performance path would then compare the log home (proposed house) to a house built with wood-frame construction according to the required prescriptive values (reference house). During the development of the prescriptive requirements, an evaluation of eleven wood-frame house types across all six Canadian climate zones resulted in an average Energuide for New Homes Rating of 78.

Snow loads – when to shovel your roof

What are signs of heavy snow load on my roof?

If you're concerned about the weight of snowfall on a roof, look and listen for signs of stress. These signs can include unusual sounds from the roof or supporting walls, visible movement of walls or sagging of ceiling and cracking of drywall or plaster. Other signs may include doors that jam or water leaks that show up after a big snow fall.

The configuration of your roof could be a factor. Pay special attention to areas on your roof where local snow accumulation occurs on a portion of a roof; for example, near dormers, valleys or on shed roofs. Roofs with a low slope or roofs covered with rough roofing material tend to accumulate more snow than steeper pitches or slippery roof finishes.

What can I do myself?

You should never clear a roof yourself. Instead, opt for a qualified and insured snow removal company. Where the roof is accessible from the ground, you can reduce some load by using a snow rake to safely pull the snow off the roof from ground level, but even then you need to be careful.

How much snow can my roof hold?

That's hard to answer – because it's not the depth of the snow, but really the weight of the snow that matters. The weight of snow can differ quite a bit; for example, compare lifting a heaping shovel of deep fluffy snow with a half-empty shovel of slushy snow. The building code requirements are based on snow load and geographic location as described in question 4. However, the same requirements may not apply to small accessory buildings such as sheds. You should monitor their snow loads as well and, if you can, rake them more regularly from the ground outside.

What are the building code requirements?

The building code requirements are based on snowfall observations converted to a snow load. The roof is designed for a combination of snow and rain load according to a table of locations in the National Building Code (NBC). The roof is then designed to support a minimum of 1 kilo Pascal (21 pounds per square foot) or higher.

Roofs on today's large buildings are designed for 1-in-50 year snow load events and take into account factors such as roof shape and accumulation. The trusses for today's houses and smaller buildings built under Part 9 of the NBC are designed according to a simplified snow load equation. This is because of the relatively smaller size and historical performance of these types of buildings.

Does the age of my house matter?

Code requirements and design methods have changed over time, as have the construction materials used. Roof trusses have been popular for several decades due to ease of construction and flexibility in design, while older roofs were typically hand-framed with rafters. That's not to say that having a 40 year old roof is cause for concern; in fact, it has demonstrated its performance over 40 winters.

What's the best way to deal with all of this?

The best way to assess the snow on your roof and to answer all your questions is an on-site visit by a local expert. You can contact a building science specialist in your area. These are typically architects or consulting engineers. In some cases home inspectors also have this expertise.

Are there other resources?

If in doubt, you can check with your local building department to determine to which requirements your house was built and whether the current snow accumulation would exceed that design load.

Here are some online resources:

Other questions

Are power driven nails addressed in the National Building Code? summary

Until recently, the National Building Code of Canada (NBC) requirements for nails and other fasteners did not explicitly address nails used in pneumatic fastening tools because the requirements were written before nail guns came into common use. The NBC 2010 was brought up to date in 2012 through the addition of a reference to the ASTM F1667 standard, "Driven Fasteners: Nails, Spikes, and Staples." This standard, which enables better harmonization with the United States, applies to fasteners driven by hand tools, power tools or mechanical devices that are currently available on the market. Essentially, the nails must comply either with the ASTM F1667 or the CSA B111 standard and, regardless of which standard they comply with, the nails must meet minimum shank diameters specified in Part 9 of the NBC.

The requirements were updated in the NBC 2015 and 2012 revisions to the NBC 2010 are available as a downloadable PDF document by filling in the form on the Revisions and errata to the National Model Construction Codes web page.

The U.S. will dramatically reduce allowable lead content in plumbing products effective January 4, 2014. Will the National Plumbing Code be revised to require low lead products as well?

The Canadian Commission on Building and Fire Codes (CCBFC) has considered a request to integrate low-lead content requirements for products addressed in the National Plumbing Code of Canada (NPC) and its Standing Committee on Building and Plumbing Services has a keen interest in maintaining harmonized solutions across North America.

A new edition of the ASME/CSA standard for plumbing supply fittings requiring the same low levels of lead content as that required for U.S. products was published In December 2012. At the same time, the CSA also published a new edition of a standard that addresses plumbing fittings, which is in line with the same low lead content requirements. Since then, the Standing Committee has reviewed the updated plumbing fittings standards and recommended updating the versions currently referenced in the NPC 2010 to reflect the most current editions. As a result, these updates were published as interim changes to the NPC 2010 at the end of 2013. As with all model code changes, it is up to the provincial/territorial regulatory authorities to consider when and how to adopt such changes into law.

Why are requirements to protect communities from wildfires not in Codes Canada publications?

Protection of communities from wildfires falls outside of the mandate of Codes Canada publications and currently established Code objectives do not address protection of property from adjacent wild land fires. The Canadian Commission on Building and Fire Codes (CCBFC) did receive a request to include such requirements in the Codes and input was sought from the provinces and territories. Based on their feedback, the CCBFC decided that the national model codes were not the appropriate mechanism for addressing this issue, as municipalities were in a better position to address it through zoning bylaws. It was noted that some municipalities were following practices introduced by Natural Resources Canada under FireSmart, a program that includes both prevention and mitigation principles to help reduce the risk of wildland fires and protect properties from their devastating effects.

Do the Codes address fire risk associated with houses built close together?

Yes. Additional fire protection requirements have been introduced in the National Building Code of Canada relating to the construction of all buildings and houses that are constructed in proximity to one another or to the property line.

For instance, limiting distances or construction requirements may need to be increased depending on fire department response times. Also, restrictions on the area and the spacing of glazed openings for houses, where the limiting distance is 2 m or less, were introduced. Finally construction types, cladding types and combustible projections such as roof soffits may also require additional protection depending on their location in the exposing building face.

These changes may have an impact on all aspects of construction, including how close the homes are constructed to each other, the nature of cladding materials used, and lot sizes in subdivisions.

Do the Codes reflect the new Health Canada guideline for radon exposure?

Yes. The Health Canada guideline of 200 Bq/m3 for indoor radon concentration has been referenced in the Part 9 Appendix of the National Building Code of Canada (NBC). Engineers and designers are now required to consider radon protection in their designs. Air barrier requirements in Part 9 of the NBC have also been consolidated, and prescriptive measures on providing a rough-in for a future radon mitigation system have been added.

How do the Codes address a sustainable built environment?

Sustainability is not an explicit objective of the national model codes. However, many code provisions contribute to a more sustainable built environment and are written with an effort to not create a barrier to future innovation. Also, Codes Canada publications do not preclude one from proposing innovative technologies as long as it can be demonstrated that these meet or exceed the minimum requirements of the Codes.

Will the use of water be regulated by the national model codes?

New requirements pertaining to water-use efficiency were added to the 2015 edition of the National Plumbing Code (NPC). New code objectives address water-use efficiency, and the development of mandatory requirements limiting the maximum amount of water used by plumbing fixtures such as urinals, and supply fittings such as shower heads.

Enabling requirements for rainwater harvesting systems are being developed for the 2020 edition of the NPC. These proposed requirements would not force the installation of rainwater harvesting systems but instead help ensure that rainwater harvesting systems perform and are configured such that persons will not be harmed by contaminated substances.

The National Farm Building Code dates back to 1995. Will it be updated?

Yes. The CCBFC has made it a priority to update the requirements of the National Farm Building Code of Canada (NFBC), last published in 1995. This decision is supported by the Provincial/Territorial Policy Advisory Committee on Codes (PTPACC) and the Canadian Farm Builders' Association.

As a result, an update of NFBC requirements into objective based code requirements is currently being conducted. Members from several standing committees formed a joint task group to review and update the provisions and examine the risks and hazards related to farm buildings. The joint task group is working towards introducing technical changes in the 2020 editions of the NBC and NFC.

Are green roofs addressed by the National Building Code of Canada?

Yes. Green roofs are referred to as vegetated roofing systems in Part 5 of the National Building Code of Canada 2015.

To protect against root penetration, the Standard ANSI/GRHC/SPRI VR-1, "Procedure for Investigating Resistance to Root Penetration on Vegetative Roofs" is referenced in Sentence

General guidance on green roofs and their performance is provided in the explanatory noteA- by referring code users to the German Landscape Research, Development and Construction Society's (FLL) "Guidelines for the Planning, Construction and Maintenance of Green Roofing" and to the National Roofing Contractors Association's "Vegetative Roof Systems Manual."

Individuals wishing to suggest other Code provisions related to green roofs can submit a code change request online at any time for consideration by the CCBFC's committees.

Designers can also propose their green roof designs as an alternative solution to their respective provincial/territorial authorities. Manufacturers of green roofs can have their products or systems assessed for code compliance by the NRC Canadian Construction Materials Centre.

What level of earthquake are Canadian buildings supposed to be able to withstand under the National Building Code of Canada 2015?

This question (what magnitude is the building designed for) is commonly asked but, unfortunately, a simple answer cannot be given. Currently in Canada, we design our buildings to withstand a certain level of shaking – the expected shaking from earthquakes that are likely to occur at a probability of 2% in 50 years, which is roughly once in 2,475 years. The effect of a particular earthquake's shaking on a building depends on the magnitude of the earthquake, its distance from the building, and the building's characteristics. For the three largest cities in Canada, here's what this means.

In Montréal, the probability of an earthquake with a magnitude greater than 7½ is extremely small, and earthquakes of this size don't make a large contribution to the seismic hazard. At the National Building Code probability levels, the main contributors to shaking hazard for short structures, such as single family homes, are earthquakes of magnitude 6¼ to 7¼ that are within 40 km. For high-rise structures the main contributors are magnitude 6½ to 7½ earthquakes at distances of 30-60 km.

Similarly, in Toronto the main contributors to shaking hazard for short structures are earthquakes up to magnitude 6 less than 40 km away, while for high-rises the main contributors are magnitude 6 to 7 events no closer than 30 km.

In Vancouver, the expected shaking from three sources of earthquakes is taken into account: those from the continental North American plate; earthquakes in the subducting Juan de Fuca plate (at depths of 40-60 km beneath Vancouver); and the very large, infrequent earthquakes of the Cascadia subduction zone. It is only the Cascadia subduction zone earthquakes that can result in a large magnitude 9 event, comparable to the 2011 Tohoku Japan, earthquake, and they only occur in Canada offshore of Vancouver Island. For Vancouver, this Cascadia event will occur roughly 140 km away, and so its effect is diminished by this distance. The main contributors to shaking at NBC probabilities for Vancouver structures are magnitude 6½ to 7½ at 50-70 km for short structures and magnitude 8½ to 9 at 130-150 km for high-rises.