Ten years ago, the “U.S.A./Canada Harmonization Task Group”, comprising twelve members—six from Canada representing the CWDMA (Canadian Window and Door Manufacturers Association) and the CSA (Canadian Standards Association) A440 Technical Committee, three from the AAMA (American Architectural Manufacturers Association) and three from the WDMA (Window & Door Manufacturers Association), began to prepare a draft North American fenestration standard. Since that time and some 14 drafts later, the “AAMA/WDMA/CSA 101/I.S.2/A440-05 Standard Specification for Windows, Doors and Unit Skylights” was included in the 2006 edition of the ICC (International Code Council) Code and is proposed to be referenced by the National Building Code of Canada. At the time of this writing, an excerpt edition of the standard has been balloted to members of that association, and was available for download at the WDMA website (http://www.wdma.com/i4a/pages/index.cfm?pageid=3710).

Current Standards for Windows, Skylights and Door Systems

A. Windows

Division B, Section 9.7. of the 2005 edition of the National Building Code of Canada  requires windows to conform to CAN/CSA-A440, “Windows” and CAN/CSA-A440.1, “User Selection Guide to CSA Standard CAN/CSA-A440-00, Windows”.

The Can/CSA-A440 standard classifies windows according to their performance in three areas—airtightness, watertightness and wind-load resistance. The User Selection Guide identifies performance ratings appropriate for buildings according to building height and the geographic area in which they are located.

Residential windows are not required to conform to the energy rating requirements of CAN/CSA-A440.

B. Skylights

Plastic skylights are required to conform to CAN/CGSB-63.14-M, “Plastic Skylights”, while factory-built glass skylights must conform to the performance requirements of the plastic skylight standard (see NBC Division B, subsection 9.7.7.).

C. Exterior Door Systems

Division B, Section 9.6. of the NBC requires insulated steel doors and their frames to conform to CAN/CGSB-82.5-M, “Insulated Steel Doors”. Sliding doors (“patio doors”) and their frames are required to conform to CAN/CGSB-82.1-M, “Sliding Doors”. Exterior wood doors must conform to the CAN/CSA-O132.2 Series, “Wood Flush Doors”—there is no standard for wood door systems).

Why a Harmonized Standard?

The opportunities of Free Trade and a relatively-favourable Canadian dollar have permitted Canadian manufacturers to market more window products to the United States. Of course, U.S. manufacturers are not blind to the opportunities North of the border either, but differing codes and standards requirements in the various jurisdictions can be a real barrier to trade. From this set of circumstances came the beginnings of the North American Fenestration Standard (NAFS) in 1997. It seems clear that, although the impetus for this change came from the manufacturing industry, a harmonized standard, provided it maintains the performance levels Canadians have come to expect, could simplify selection and regulation of these products. Who knows? The increased competition might even lead to enhanced quality or better prices for consumers.

Role of Task Group

In December, 2006, the “Joint Task Group on the Harmonized Window, Door and Skylight Standard 101/I.S.2/A440 Windows, Doors, Unit Skylights” convened its first meeting to consider a request for a change to the NBC, submitted by the Canadian Standards Association. The request is to replace window, door and skylight references in the NBC with references to the new harmonized standard. The Task Group includes representatives from the Part 5 (Environmental Separation) and Part 9 (Housing and Small Buildings) Technical Committees of the NBC.

The task group’s terms of reference are to compare the new standard to the currently-referenced standards, and to compare the new standard to the scope, application and objectives of the building code provisions that would reference the new standard.

The report of the Task Group will contain recommendations on how to deal with its findings. The Part 5 and Part 9 Standing Committees will then decide on appropriate actions.

How Harmonized is the New Standard?

A Canadian supplement (“A440HS-1 Canadian Supplement to AAMA/WDMA/CSA 101/I.S.2/A440-05”) is being prepared by the CSA Technical Committee, which will contain additional requirements to the harmonized standard to maintain established Canadian performance levels and to make Canadian application of the harmonized standard consistent with the 2005 edition of the National Building Code of Canada.

A look at the Table of Contents for the Canadian Supplement shows that there will be a Canadian flavour to, among others, requirements for:

-         Insect Screen Serviceability Test,

-         Operating Force Requirements,

-         Air Leakage Performance,

-         Water Penetration Resistance Test,

-         Steel Door Facing,

-         Steel Door Frames,

-         Steel Window, Skylight and Door Sash and Frames,

-         Lock Blocks,

-         Markings,

-         Performance Rating,

-         Specified Driving Rain Wind Pressure (DRWP) for Open Terrain, Rough Terrain, and

-         Specified Wind Load for Windows and Doors.

The fact that the Canadian Supplement is quite extensive, and that the standard itself contains some "Canada only" tables, as well as the fact that American (marketing) classes with superimposed air leakage ratings remain in the standard might lead some to wonder how “harmonized” the standard really is. It is only to be hoped that, as the years pass, the best of the Canadian Supplement will be absorbed into the body of the standard, and that harmonization will become fact.

Who’s in Charge?

Currently, the CSA is responsible for the A440 window standard while the CGSB is responsible for skylight and door standards. It isn’t clear whether CGSB will devolve responsibility for their standards to CSA should the NBC reference the harmonized standard.

Schedule for the Decision to Reference the North American Standard

If the “Task Group on the Harmonized Windows, Doors and Unit Skylights Standard” should recommend it, and should the Part 5 and Part 9 Standing Committees agree, we should see the harmonized standard replace window, door and skylight references in the next edition of the NBC—in 2010.

Some Possible Implications of Referencing of the North American Standard

-         Site-built door systems (i.e. wood doors with site-built frames) might be proposed for inclusion in the harmonized standard at a future date. At present, site-built door systems are not addressed by the NBC. It should be noted that wood, exterior doors have pretty-well disappeared from the marketplace, so the point might be moot (love that word!).

-         The Can/CSA-A440.4, "Window and Door Installation" standard might be proposed for reference by the National Building Code. At present, this standard is not mandatory in the Code.

-         Changes from the A, B and C ratings in the CSA A440 standard to the tighter and more continuous rating system in the harmonized standard could provoke some discussion in the industry.

-         The NBC standing committees could be asked to require conformance to the condensation-resistance provisions of the harmonized standard (also contained in the current CSA A440 standard), and that compliance be demonstrated by simulation or testing.

These and other potential issues will, I’m sure, be discussed thoroughly by the NBC Standing Committees, and will be resolved before a decision is taken on referencing the harmonized standard.

Acknowledgement

Many thanks to Frank Lohmann, Technical Advisor in the Canadian Codes Centre for suggesting this topic and for providing information and advice.

For Further Information

-         Canadian Codes Centre: http://irc.nrc-cnrc.gc.ca/codes/home_E.shtml,

-         Canadian General Standards Board: http://www.pwgsc.gc.ca/cgsb/home/index-e.html,

-         Canadian Standards Association: http://www.csa.ca/standards/Default.asp?language=english,

-         Canadian Window and Door Manufacturers Association: http://www.cwdma.ca/,

-         Window and Door Manufacturers Association (U.S.): http://www.wdma.com/i4a/pages/index.cfm?pageid=1,

-         American Architectural Manufacturers Association: http://www.aamanet.org/.