Household arrangements selected by families and individuals throughout their life cycle are highly dynamic. In most developing countries, especially among low-income groups, domestic groups frequently do not follow a nuclear family pattern. Extended household forms can be viewed as a response, or a strategy, to the problems of under-employment and under-remuneration faced by a number of families. They also reveal ways of adjusting to changes in the family life cycle. These perspectives have not been taken into account in most housing plans for low-income families. The chapter describes the general aspects of household arrangements. It analyses the determinants of non-nuclear households in low-income communities. The chapter discusses how the structures help families face the conditions of poverty. It focuses on the implications of household patterns for household policies. The chapter shows that the policies give more flexibility to poor families for household arrangements.