I doubt that the state will be more efficient in building houses than private enterprises can if allowed to do so. If they are not being built and added on marked, the effective price will only crawl up.
In case if Zurich, I imagine that supply is limited due to its geography as well, and of course by wanting to preserve the quality of life.
> I doubt that the state will be more efficient in building houses than private enterprises can if allowed to do so
Depends. If the profit is in more expensive housing, than private enterprise will bias towards that and ergo be less efficient at building lower-margin "affordable" housing.
Ideally, in a perfect frictionless economy populated by spherical cows, yes, private enterprise will more efficiently allocate across the entire spectrum of market needs -- so in principle, I'm agreeing with you.
In case if Zurich, I imagine that supply is limited due to its geography as well, and of course by wanting to preserve the quality of life.