There are more people approved for mortgages than there will be new houses for them to buy.
Around 20,000 first time buyers have been cleared for a mortgage this year - but only half of this number of new homes are for sale.
€2bn in mortgages got the go ahead in the first three months of the year, almost double the amount for the same time last year.
The average approval amount was €214,400 in March, up 9% on last year.
It is reported that this house shortage could push up prices by as much as 10%.