PART 254—POSTAL SERVICE STANDARDS FOR FACILITY ACCESSIBILITY PURSUANT TO THE ARCHITECTURAL BARRIERS ACT Authority: 39 U.S.C 101, 401, 403; 29 U.S.C. 792(b)(3) and 42 U.S.C. 12204. Source: 70 FR 28214, May 17, 2005, unless otherwise noted. § 254.1 Adoption of U.S. Access Board Standards as Postal Service Standards of Facility Accessibility. (a) The United States Postal Service adopts as its Architectural Barriers Act (ABA) “Standards for Facility Accessibility,” the following sections of 36 CFR part 1191: Appendix A to Part 1191, Table of Contents for apps. C, D, and E. Appendix C to Part 1191, Architectural Barriers Act, Scoping (which contains ABA Chapter 1, Application and Administration, and ABA Chapter 2, Scoping requirements); pertinent parts of Appendix D to Part 1191, Technical (which includes Chapters 3 through 10). Appendix E to Part 1191, List of Figures and Index. (b) These sections listed in paragraph (a) of this section are adopted verbatim, with the exception of the Advisory Notes, which are expressly excluded. § 254.2 Definition of primary function area and criteria used to determine whether an alteration has an effect on an area containing a primary function that is disproportionate to the overall alterations. (a) Terminology. (b) Primary function areas. (c) Disproportionality. (2) For purposes of the accessibility guidelines applicable to the Postal Service under the Architectural Barriers Act, two criteria must be considered in making a determination whether accessibility improvements are disproportionate to the cost and scope of the original alteration: a magnitude threshold for the original alteration and a maximum “percentage threshold” for the accessibility alteration. (d) Magnitude threshold. (e) Percentage threshold.