In the past twenty-five years, in France, the share of housing expenses incurred by households in their total budget has increased considerably. It became the first budgetary margin, far beyond food. At the beginning of the eighties, these two expenses respectively represented 14 percent and 15 percent of households’ budget. In 2004, these proportions were 21 percent and 12 percent (Plateau, 2006) whereas housing can be considered as a “forced cost” (Fabre, 2007). In addition to this quantitative transformation, there is also a more qualitative transformation in terms of lifestyle. As a matter of fact, in 1980 as during the beginning of century (Halbwachs, 1912), the budgetary margin of housing (energy excluded) was independent from households’ budgets. But in 2000, housing, common law, and basic good became an inferior good since the share of housing expenditure in household budgets increases when income decreases. This result suggests that the more underprivileged categories of population have recently been constrained by the pressure of housing in their budgets.