For what it's worth - you come across as completely unserious if your suggestion to fix housing shortages is genuinely to levy a $100k tax for property owners who aren't currently renting out their units.
Nobody is going to build houses and sell them at a loss or at break-even price, they need to cover their costs and make some profit as well to keep the business alive.
A lot of people in here arguing, bet there are very few of us that have actually built houses before :)
He also mentioned that new requirements going into effect this year were going to add $10-15k per house.
People tend to have a poor grasp on what building a new house actually costs. They cost a lot to build with no gouging whatsoever.