Provides an updated revision to ANSI/AAMA/NWWDA 101/I.S.2-97, which has enjoyed wide acceptance in the United States since its publication. Like its predecessor, the North American Fenestration Standard (NAFS1) is a material-neutral, performance-based specification for wood, vinyl and aluminum windows and glass doors. The specification establishes performance criteria for multiple tiers of product rating and classification, in response to the wide variety of end use conditions fenestration products encounter across the United States and Canada. In addition, specific requirements for all operator types are given. The revised specification also includes many improvements and additions. The addition of skylights, specialty products, sidelights and transoms to the standard brings the total number of operating types recognized in the standard to 26. While product ratings have remained in the familiar format accepted in 101/I.S. 2, the remainder of the standard has become metric in format. The introduction of metric-based requirements instead of metric conversions of inch-pound (IP) requirements was done as a part of efforts to harmonize the standard not only with Canadian standards but also international standards such as ISO, JIS and CEN standards. It is also consistent with US Federal directives concerning metrification of construction products. The format has been revised and explanations have been added to make it easier to find and use specific requirements, and the requirements have been updated to reference the newest test methods available for the industry. NAFS now contains 55 illustrating figures and 80 tables to clarify the requirements of the standard. In addition a new four-page spreadsheet has been added that completely outlines all testing requirements and minimum performance levels included in the standard.