Exposure Categories

Exposure B

Urban and suburban areas, wooded areas, or other terrain with numerous closely spaced obstructions having the size of single-family dwellings or larger.  This exposure is limited to areas where the terrain has obstructions that surround the structure in all directions for a distance of at least 2,630 ft (800m) or ten times the height of the structure, whichever is greater.

Exposure C

Open terrain with scattered obstructions having heights less than 30 ft (9.1m).  This includes flat, open country, grasslands and shorelines in hurricane prone regions.

Exposure D

Flat, unobstructed shorelines exposed to wind flowing over open water (excluding shorelines in hurricane prone regions) for a distance of at least 1 mile (1.61 km).  Shorelines include inland waterways, lakes and non-hurricane coastal areas.  The Exposure extends inland a distance of 660 ft (200m) or ten times the height of the structure, whichever is greater.