The distance from the edge of a coastal bluff or bank (or other reference point) to a building or other structure is called a setback distance. Selection of a setback distance is one of the most important decisions that a homeowner or builder can make when building a coastal home. The setback distance may determine the life of the building.
Evaluating the safety of an existing setback distance is equally important when deciding whether or not to purchase a coastal home. Many coastal homes being built at present have such large footprints that they are prohibitively expensive to relocate as erosion threatens their existence. Large setbacks are a preferred alternative to demolition for such buildings.
Shore protection and bluff or bank stabilization are costly measures to prevent the retreat of coastal land. The cost is comparable to the cost of coastal land. On the Great Lakes, lakebed erosion in some locations and the freeze-thaw fracturing of armor stone accelerate the deterioration of most types of shore protection structures.
There are different reasons for choosing the distance that separates the edge of a coastal bank or bluff from a building or other structure that is planned for construction. This is also true in considering purchase of an existing coastal structure. The reasons selected depend on the situation and the perceived risk to investment in the structure.