A new report by Focus Ireland shows the homeless charity supported a record 14,500 people last year.
The Family Homelessness End of Year Review 2017 shows the homeless charity helped over 1,000 people exit homelessness and move into new homes last year.
Focus Ireland said the number of homeless families increased by 31% from over 1,300 families to over 1,700 families in the year to May 2018.
It said there has been a decline in the number of private rented properties on the market and in the number of social houses available which is stopping people from getting out of homelessness.
The organisation is calling on the Government to significantly increase the amount of housing which is being built by Local Authorities and Approved Housing Bodies.
It is also calling for the introduction of measures to prevent buy-to-let landlords from evicting tenants in order to sell a property or move in family members.
Focus Ireland also said the Government must revisit proposals to make the thousands of vacant properties around the country available.