This review of affordable housing explains the many factors instrumental in slowing construction, thus producing today's shortage of new homes. The availability of affordable mortgages; the efforts of home building companies; the state of the economy at any particular moment; and the cooperation, or otherwise, of local authorities and planners - all have played a part in producing a situation where widely available new housing has given way to unaffordable housing for those wanting to take the first step up the homeownership ladder.