You cannot accurately predict population growth. It varies according to economic and political situations. Housing availability may also alter because of baby boomers dying off in 10 years or so. Pensioners are often living in houses that are now too big for them now that the family has left - my mother lives alone in a 3 bedroom house. No wat are we going to move her unless absolutely necessary. You could say that she and people like her are partly to blame, but I do not want her to live in a home as the house is her home. There are also more single households than previously, which means more individual flats/ homes. It is hard to estimate how much and what sort of housing will be needed or become available in the future, but as a general guideline, we need affordable housing which will not necessarily be the target of private developers. They make more out of low volume, but high price developments. There is an argument for more state subsidised development.