Facilitating home ownership and providing more affordable housing has received considerable attention in urban China. However, it remains a challenge to develop better measurements of affordability due to the income disparity and housing inequality in Beijing. In this study, a new measure of affordability is defined by residual income. Therefore, a minimum required budget for a family to purchase a “standard” unit is deduced by accounting for the basic necessities and financial loans. This paper also discusses the deficiencies of the implemented “Economic Housing Plan” on bridging the housing affordability gap.