I'm not sure, the UK has relaxed it's planning laws in recent years but house building seems tied to the general economic cycle and way below what we really need.
Yes but because land is so dear it tends to be the case that only high-end homes get built - ie expensive and low density.
The basic problem is that land & housing prices are too high relative to people's wages. I think the reason they are so high is because of government intervention in the finance & housing markets.
