MCRP 12-10B.1, page 88

Have thick walls Be constructed of nonflammable materials Be strategically located (corner buildings and prominent structures) Be adjacent to streets, alleys, vacant lots, and park sites (these buildings usually provide better fields of fire and are more easily tied in with other buildings) Provide for 360-degree protection and fields of fire Be stocked with adequate supplies as positions may become isolated and cut off for extended periods. (2) Assign Sectors of Responsibility. Boundaries define sectors of responsibility. Sectors include areas where units may fire and maneuver without interference or coordination with other units. Responsibility for primary avenues of approach should never be split among units. In areas of semi-detached construction, where observation and movement are less restricted, boundaries should be established parallel to alleys or streets so that both sides of a street will be in a single sector. Where buildings present a solid Military Operations on Urbanized Terrain 3-17