Any suggestions on how to make that happen? People are already free to build as many houses as they want. They don't because building houses is expensive and there are easier ways to make more money with that capital
At (inflation adjusted) price X in location Y + regulator time/cost Z, the number of housing units that can be legally built has decreased considerably. Part of this is we've exhausted undeveloped/raw land and haven't upzoned in most locations.
The fixed costs and regulatory hurdles for building housing units can certainly be reduced - if the political challenges can be overcome.
Even some relatively sane regulations like insulation and safety standards could be re-evaluated. The issue is we are not doing any cost-benefit analysis of these regulations; even a 10% increase in the average home price should logically have a large impact on overall quality of life; that extra 10% spent on housing (~$50,000) in young adulthood reduces retirement savings >$300,000 assuming 8% returns, 30-40 years of investment, etc.
Pass a regulation saying any building permit application that isn't reviewed in 10 days is default approved. Then defund the permit offices.
In tandem, gut the ability for anyone to file suits (I'm looking at you, CEQA) that block development.
source: two years in a professional US urban planning office