People in larger social houses shouldn't get to stay in them for life when growing families need them.
Financial analyst Karl Deeter said there can be several approaches to helping people to downsize as they get older.
It comes as an ESRI report finds that 67% of Irish households live in under-occupied housing - meaning they are in homes that are too big for their needs.
It finds that housing units in Ireland are, on average, bigger when compared with other European countries.
According to Eurostat 'a household is under-occupied if it has at its disposal more than a minimum number of rooms considered adequate'.
With an under-occupancy rate of 67.3%, Ireland is in the top three in Europe in terms of under-occupancy - along with Malta and Cyprus.
Financial analyst Karl Deeter told The Pat Kenny Show the findings are not surprising.
"I did studies on this I would say nine years ago when I was looking specifically at social housing to show how disgraceful it was that we had thousands of examples of one person being in a three-bed house, while we also had hundreds of examples of a family of six living in a one bed," he said.
"I was trying to make a point that we need to find a way to re-profile that housing, to more effectively use our State-owned housing stock.
"It caused a bit of uproar at the time but that's just part of life."
'Act of social grace'
Mr Deeter said people downsizing should realise they are attached to bricks rather than people.
"It can also be looked at as being an ultimate act of social grace to free up a house for a family of six that might be living in a one bed," he said.
"It can also be viewed that your memories are not actually attached to bricks and mortar, it is attached to the people that you love and that's your community".
Carrot and stick
Mr Deeter said he believes there are two approaches to downsizing.
"One would be the stick version.... which is that people need to pay more appropriately on the property tax and on their social rents," he said.
"Another would be to say we need to make more social housing that is smaller; but even if you did that I'd suspect you still have a lot of people who don't want to move.
"Moving is a total pain, no one wants to do it and if you can avoid it you would".
'End homelessness tomorrow'
Mr Deeter said people in larger, State-owned housing shouldn't have a carte blanche right to stay there.
"We could theoretically end homelessness tomorrow if we managed our State-owned housing correctly," he said.
"That is factually true and it's a really upsetting statistic after all of the news that we hear day in, day out about homelessness.
"We have so much vacancy in the social housing stock in terms of extra rooms that people are under-occupying."
'It's owned by the State'
Mr Deeter also likened the housing crisis to a shortage of hospital beds.
"To an extent this is like hospital beds - you can't just say, 'I want to occupy this hospital bed forever'" he said.
"There's other people who need that asset and it is owned by the State, it's not owned by the person.
"I think the idea of giving people tenure for life when they qualify for it one time that's questionable," he added.
Mr Deeter said he believes he'll be talking about the same issue "20 years from now".
Listen back here:
