In a broader perspective, I think we have to realise that we are not only seeing the results of a the population increase here.
Since the 1970s family homes have tended to become larger, as families were no longer content to have sisters or brothers sharing rooms - each child in a family had to have his or her room. Bathrooms are another point - in our childhood you were fortunate if you lived in a house that did have a bathroom, and it was even better if there was both a bathroom and and extra toilet, now a lot family homes have more than one bathroom and other non-essential rooms such as a utitily room, a hobby room etc. etc.
I am not saying that we should go back to living four adutls an three children in two rooms and a kitchen with the toilet on the staircase and shared with three or four other families. but we could perhaps make do with just a little less space per family, thus perhaps decreasing housing costs.
Another change in lifestyle is that there are many single people living either in four or five roomed flats or in houses, alone, or with children or a partner coming at weekends.
If none of us are prepared to consider sharing our accomodation with others, obviously this will only increase the shortage of available housing.
Points worth considering, but I admit, I do not have a solution.