A quarter of people know of someone impacted by 'hidden homelessness', or have even experienced it themselves, according to the Simon Communities of Ireland.
A Red C opinion poll, conducted for the charity, also found that 18-34-year-olds are significantly more likely to report an experience of hidden homelessness themselves, in contrast with those aged 55 and over, who did not record the experience at all.
The poll of 1,015 respondents found that 26% of people either reported hidden homelessness themselves (5%), or knew of family, friends, or acquaintances affected by the issue.
The vast majority described their living situation as being ‘unintended’ and ‘without a clear leaving date’.
The situation was most prevalent among 18-to-24-year-olds, where 12% of the group said they knew of someone staying temporarily with another household as they do not have a regular address of their own.
Some 9% of the same group saying they knew of a family member in that position.
It also found a higher level of uncertainty among those classified as lower social grades, as to when the situation will end for those affected.
According to the poll findings: "These results are perhaps even more poignant given the lack of available housing, rising energy costs, and economic forecasts for continuing rise in inflation through 2023.
"This highlights the precarious nature of the situation should economic conditions worsen, which at present it seems likely."
The record levels of homelessness recorded in the monthly report for July come amid a striking rise in the number of people — particularly men — aged 18 to 24 living in emergency accommodation over the past year.
Organisations including the Simon Communities have raised concerns that hidden homelessness — including people couch surfing, and moving between staying with friends and family — may not be reflected in the official homelessness figures.
Simon Week begins on Monday, and Wayne Stanley, head of policy and communications at the Simon Communities of Ireland, said a Covid-style response to the crisis in housing was needed, with "bold steps" needed to address the problems.
He said tackling vacancies would be an immediate step, and other issues that needed considering included growing on-campus student accommodation, to help ease the pressure on the private rental sector.
Simon Week’s ending homelessness campaign begins with a conference today, that will focus on issues including single person homelessness, the lack of supply of housing, and the frontline experience.