Housing affordability is an increasingly important problem in cities around the world. In Europe, approximately one in ten families spend more than 40% of their income on housing costs, a situation referred to as “housing overburden”, which is particularly acute in cities (Eurostat, 2021). In Spain, 20% of tenant households are overburdened by housing costs, spending over 40% of their income on housing (OECD, 2021). The
extent and importance of this phenomenon has led to the coinage of the term “housing affordability crisis” (UN-Habitat, 2020).