Leo Varadkar said that this compares to 10% of new homes being bought by investment funds "in the last year gone by".
Taking Leaders' Questions, Mr Varadkar said that the Government wants to avoid taking any measure that will result in fewer apartments being built.
"I've been living in an apartment for 14 years," he said, and as an owner-occcupier he said he knows that apartment are homes.
"Those of us who live in apartments are not 'transients'", he added, referring to two remarks made by Sinn Féin Senator Lynn Boylan. Mr Varadkar called on her to withdraw the remarks.
The Tánaiste was responding to Sinn Féin's Pearse Doherty, who said that half of all homes built in last year were apartments, and that rose to 60% in Dublin City.
One firm made €75m in rental income and paid no tax, he said.
"Apartments are homes just like houses", he added, criticising the Government's failure to reign in price increases.
"Your message to those who want to buy a home that is affordable is 'Sorry, not on our watch'", says @PearseDoherty@LeoVaradkar says apartments were not included in measures to reduce bulk buying, as many wouldn't be built without investors to buy themhttps://t.co/IyArcIvpHm pic.twitter.com/RwJQP1iseY— RTÉ News (@rtenews) July 1, 2021
Yesterday's news revealed that 398 homes in three locations in Dublin "were snapped up by these funds", he said, noting not one of those funds will have to pay "the increased stamp duty" the Government is introducing.
"You need to calm down", Mr Varadkar said, accusing Deputy Doherty of a planned display of "histrionics and anxiety every Thursday" for the benefit of social media.
"Everyone knows it", the Tánaiste said. "You don't really care".