Our housing availability problems are brought to you by AirBnB, et al.
Far too many houses are being bought up by business ventures for rentals (short or long-term), cutting the available supply for people who simply want a home.
Simple solution here is to 2x or 3x the property tax rates on homes that are not your primary residence. You get 1 primary residence for 1x rate. Up those rates for "vacation" homes and rental homes. Eliminate tax breaks for rental properties that are not zoned as apartment dwellings. As costs for those go up, people will sell them back on to the regular housing market. Figure out ways to make that happen, to free up properties for sale as primary residences.
You can grandfather out seasonal vacation rentals/cabins, etc. Target the ones in regular, residential areas. That will generate more available new housing than building can or will.