The Government is being urged to declare a national homeless emergency.
Hundreds of people are expected to protest in Dublin city centre today - to highlight the scale of the problem.
Recent figures show there are more than 2,000 children across the country who are registered as being homeless.
While some adult hostels say they have been forced to take in youngsters and place them on blow-up beds.
IMPACT's Joe O' Connor is one of those organising today's march - he has said the state needs to take extraordinary measures to deal with the crisis: “Well this is something that will require not just one minister or one Government department or one measure to fix.
“Obviously it is a multi-faceted problem, what we are calling on today is that we believe a housing emergency should be called, which would allow the Government to an all of Government approach to trying to solve this crisis situation.
“Also would allow them to divert the necessary resources into tackling the housing crisis.”