Another possible solution that many won't like, are a type of government renovation grants. This would apply to older homes (say 50 years old) and they would enable people on a fixed income a better ability to buy an affordable house and modernize it. Obviously you would make some stipulations to make it only available to families/individuals using as a primary residence and limit the oners ability to move within a certain amount of years without penalty.
This would help address many of the older homes in a state is disarray that sit on the market for a long time. Often times flippers will buy these houses for cheap, slapping some cosmetic fixes on them, and then re-sell it 3 months later at a 50% (or higher) mark-up, which in turn drives up the prices in the surrounding area. This is another issue that is making affordable housing a problem.
But again, it's the government giving money away and a plan not guaranteed to work. Seems easier to just build more homes.