The rapid expansion of the Washington area in recent years, particularly in the outer suburbs, has spawned fears that uncontrolled growth endangers the environment, aggravates transportation problems, and makes inefficient use of existing infrastructure. One alternative to suburban growth is to have a larger share of the area's residential expansion in the District of Columbia. Moreover, such an alternative is consistent with Mayor Williams' and other District officials' optimistic projections for an increased city population in coming years. To make this happen, however, new housing construction or rehabilitation of vacant housing in the District will have to increase by a substantial number of units.