This is a positive feedback loop. Low rates make it easy to borrow $$ to build houses. People must be housed = they will find ways to pay that rent.
The only way to stop a runaway train = apply brakes.
In this situation you need to extract money from the buy-at-low-rate + rent-it-out cycle.
Best way is to extract taxes by applying business taxes or hotel taxes to rented units(short or long term) to break that positive feedback cycle.
Then land and house prices will decline to affordable levels