North American Fenestration Standard -- Only Online DWM July/August 2006

Only Online -Door and Window Manufacturer July/August 2006

North American Fenestration Standard
New Draft Fine-Tunes Performance
by Jeffrey F. Lowinski

Consensus doesn't come easy, but it's what the Window and Door Manufacturers Association (WDMA) does best-works on bringing all parties together for a common good, especially when it comes to promoting the best interests of the door, window and skylight industry.

As a code advocate, we work hard to bring standards to the industry that will allow our manufacturers' products to perform in construction projects as they are intended, standing up to the rigors of continuous use or even Mother Nature.

As codes change and evolve, so do WDMA standard and certification programs. In fact, we view our standards and test methods as a work in progress. These documents need to continue to morph and adapt to the changing construction environment, as well as other building circumstances, as they arise.

Although it was just released in 2005, AAMA/WDMA/CSA 101/I.S.2/A440-05 Standard/Specification for Windows, Doors and Unit Skylights is being revised and fin-tuned, updated to bring more real world pertinence to it as a document.

NAFS is Back
It's back to basics. The first version had North American Fenestration Standard (NAFS) as part of the title, while the 2005 publication did not include it in the name of the document. Adding that title back to the 2007 standard to keep a recognizable, consistent recognition in the industry is one of the changes proposed to the revision.

The publication was, and remains, a "first" for many reasons. It was forged by three major associations and their representatives together. The result being a document that, at its core, is solid and targeted at the industry, but still holds enough flexibility to adapt itself to the use of newer and more modern materials, processes and testing procedures. It was, and still is, the first all-encompassing publication to deal with doors, windows, unit skylights, and also, side-hinged exterior doors, allowing the building envelope package to come full circle in the standard.

As we move WDMA forward, focusing on performance attributes and how they apply to the actual world of construction is always at the forefront of our efforts but especially in these documents, which we hope the codes community will continue to reference.

The U.S./Canada Harmonization Task Group (HTG) has completed proposed changes and begun balloting, with the goal of submitting the revised document for code adoption and reference in the 2009 edition of the International Code Council (ICC) I-Codes. Some of the changes may not make it into the codes until the 2012 edition, because of the length of time needed to get the necessary industry approvals.

Changes Aimed at Simplification
The draft changes are intended to simplify and promote adoption of the standard by architects, designers, specifiers and builders, creating further solid ground for the professional application of these products. Some of the most notable proposed changes include:

Reducing the number of Performance Classes (R, LC, C, HC and AW) from five to three, eliminating LC and HC;
Introduction of a new minimum test size option. This will allow a product to enter Performance Class R by testing a specimen of an alternative minimum test size, smaller than the historical "gateway" size, provided that the minimum Performance Grade is increased accordingly. This option was created to allow manufacturers to more consistently test actual production sizes, while at the same time maintaining reasonable equivalence to the benchmarks that have been established by the predecessors to 101/I.S.2/A440;
Inclusion of Tubular Daylighting Devices (TDDs), also called sun or solar tunnels, with specific type and performance requirements established for the products. These devices have seen increased popularity as users continue to add light-letting products to their construction projects; and
Changes proposed by WDMA in the Voluntary Performance Rating Method for Mulled Fenestration Assemblies AAMA 450-06 will be referenced in the 101/I.S.2/A440-07 edition of NAFS. A mulled fenestration assembly is defined as two or more products combined and installed in one opening. Prior to the changes proposed by WDMA, there was no defined procedure for determining the performance of these types of assemblies although they have become commonplace with vast expanses of windows.

The changes are designed to make 101/I.S.2/A440 easier to use, focus more fully on performance throughout and continue to bring high standards of excellence to the manufacture of windows, doors and unit skylights. Truly, it is, the North American Fenestration Standard.

Jeffrey F. Lowinski serves as acting president of the Window and Door Manufacturers Association based in Des Plaines, Ill. He may be reached at jlowinski@wdma.com.