Housing bubble is caused by flippers in the main, running around buying up houses in big numbers, and on the West Coast Asians are paying high prices for houses here in the U.S.
As for the claims of some kind of 'shortage of skilled workers', that's nonsense. Houses have gone up on lots within 4 blocks of my house, and all four are still empty after several months of being on the market. Overbuilt and over-priced for the area. Several others, older homes, have been sold, gutted and remodeled, some sold, some still on the market. again over-priced and speculators will probably go into bankruptcy rather than price to sell, same as in the last bubble, and let the Fed eat the loss, like good little 'free market' business-people everywhere always do.Then blame left wingers because their hustle failed.