Among the changes in the new fenestration specifications now under public review are the elimination of the commercial grade for windows, leaving only four grades—residential, light commercial, heavy commercial, and architectural, that will be designated by letters alone: R, LC, HC, and A. One result may be lowered standards for certain HC window-performance characteristics. The public-review period runs to February 28. If you have any comments, please be sure to send them (or copy them) to David Collins, FAIA, who is coordinating the AIA response.

The changes to the voluntary standards are a joint effort among the American Architectural Manufacturers Association, Window & Door Manufacturers Association, and Canadian Standards Association. They would replace the current North American Fenestration Specifications (NAFS-1). If, as expected, the American National Standards Institute accredits the revised standard, it will go before the International Code Conference for adoption into the 2006 International Building Code. Canada is also expected to adopt the standard into its building regulations.

The draft standard was recently renamed from NFAS-2 to 101/I.S. 2/A440-XX (where XX will be the copyright year once that is determined). Once accredited, 101/I.S. 2/A440 will be the first complete fenestration specification for windows, doors, and unit skylights for both the U.S. and Canada.

Both the juxtaposing of the Canadian and U.S. standards and the streamlining of the current standards inspired the many changes between NAFS-1 and 101/I.S. 2/A440-XX.

In a synopsis of the merging of five product classes into four, Window & Door Manufacturers’ Association (WDMA) Director of Industry Standards Rick Perry wrote in the WDMA newsletter that:
• The new (HC) class will maintain the L/175 deflection limit requirement
• The gateway test sizes of the new (HC) class will be the same as the previous (C) class sizes
• The new (HC) Class will now require the auxiliary tests previously associated with the old (HC) class products
• The minimum performance grades for each class were revised as follows
R—750 Pa (15.7 psf)
LC—1250 Pa (26.1 psf)
HC 1750 Pa (36.6 psf)
AW—2250 Pa (47.0 psf)
(Although the actual pressures are in Pa, the designators will remain: 15, 25, 35, and 45.)

Copyright 2003 The American Institute of Architects. All rights reserved.