Housing affordability can be broadly defined as the ability of households to buy or rent adequate housing, without impairing their ability to meet basic living costs. Yet the reality is more complex, both in terms of the metrics used to measure housing affordability, as well as the policies introduced to make housing more affordable. As discussed in this brief, some measures provide an indication of housing affordability among the median household, while others are better suited to assess the challenges facing specific groups, such as low income households, youth or seniors.