Opinion ID: 70274
Heading Depth: 3
Heading Rank: 2

Heading: Terrain Exposure Categories

Text: 76 Because wind damage to structures is affected by natural topography and man-made construction, the ASCE 7-88 standard, which the agency adopted as the basis for the new regulations, establishes four terrain exposure categories to reflect the surrounding terrain in which a structure is to be sited. These exposure categories can be briefly described as follows: Exposure A: large city centers; Exposure B: urban, suburban, and wooded areas; Exposure C: open terrain with scattered obstructions; and Exposure D: flat areas exposed to wind approaching over large bodies of water. 77 The manufacturers argue that the new wind regulations are arbitrary and capricious because they impose on all manufactured homes, regardless of the actual exposure category in which the homes may be located, standards that are based on Exposure C areas. For example, they say that even though 80% of the area in Dade and Broward Counties in Florida qualifies as Exposure B, manufactured homes located there must meet the stricter requirements for the Exposure C category. Thus, the manufacturers argue, the wind regulations are arbitrary and capricious because they ignore the statutory criterion that the standards be reasonable for the geographic region for which [they are] prescribed. 42 U.S.C.A. Sec. 5403(f)(3) (West 1983). 78 HUD has provided a sensible explanation for adopting a single exposure level for the new wind standards. It chose Exposure C in the reasonable expectation that most of the manufactured housing will be located in Exposure C conditions. Although HUD could have permitted homes located in Exposure B areas to have somewhat more lenient standards and could have required homes located in Exposure D areas to have somewhat more stringent standards, we cannot conclude that it was unreasonable to choose an intermediate exposure category that provides reasonable protection for all areas in Wind Zones II and III. 7 HUD explained that it chose a single exposure category so that dealers could stock inventories, and would not be required to order each home based on the individual customer's location. Because HUD neither refused to consider the appropriate factors nor committed a clear error of judgment, the agency's decision to adopt Exposure C wind standards for all Wind Zone II and III areas was not arbitrary and capricious. 79