To give my thoughts on the original question because it has been almost entirely ignored.
This is clearly an unexpected and unusual situation and for that reason unlikely to be replicated in the sense that councils are not going to go around buying expensive buildings and turning them into social housing, it just doesn't make sense.
It probably isn't productive to have large areas where ordinary people are completely priced out of the market but this ship has already sailed unfortunately. As a country we push home ownership to an obsessive level yet we have found ourselves sleepwalking into a situation where, in lots of different parts of the country, wages simply do not allow it if you want to live anywhere near where you work. I live in an town where a single teacher/fireman/policeman/nurse would be unlikely to find themselves in the position to buy a one bedroom flat, that wage:property price ratio is a complete killer.