More than half the population of Spain live in houses designed for others. Nearly all the housing units available follow a specific design according to the requirements of a nuclear family, which is no longer the living arrangement of the majority.

This specific design makes it difficult to adapt to the new needs, be it those of the 24% of Spaniards who live alone, or those needing space for working at home, or independence for members of the recombined families, or the needs of older people whose children live far away.