An unexpected gain of 191,000 foreign migrants last year and higher immigration forecasts this year and next by the government’s key population body threatens to increase the country’s forecast housing shortfall and push up rental prices in an already white-hot market, economists warn.

New housing approvals fell to a decade low and loans for the construction of new homes dropped to their lowest in 15 years in January and revised forecasts by the federal government’s Centre for Population mean an even tighter rental market as the pipeline shrinks, economist Louis Christopher said.