The lowest-paid workers are paying the highest portion of their income on housing costs, the Oireachtas Committee on Housing has been told.
The Economic and Social Research Institute (ESRI) told the committee that their research found that households in the lowest 25% of the income distribution were paying nearly 40% of their income on housing payments, compared to the average of 20%.
These figures did not include the cost of other housing services or utilities.
Dr Conor O'Toole said their research also explored how much income households' had left after they paid their housing costs and tested whether this would be sufficient to purchase a minimum standard of living in terms of goods and services.
"We find many low and middle income households would have insufficient resources after housing costs to do so," he said.
"We also find that for many low-income households, even if their housing cost is low, they have few resources left after making their monthly rent or mortgage payment".
The ESRI also said there was a need to review rent limits for the Housing Assistance Payment (HAP) more regularly due to the variations in support to households with identical circumstances across local authority areas.
The committee was also told by the CEO of the Housing Agency John O'Connor, that a new affordable purchase scheme is about to commence.
Mr O'Connor said the Minister for Housing intends to give "full effect to the scheme in the next number of weeks" and the regulations underpinning are due to be announced shortly.
The committee also heard from the Ó Cualann Cohousing Alliance, a not-for-profit company with their own affordable housing scheme behind the Poppintree development in Ballymum in Dublin.
The company's CEO Hugh Brennan said access to land is crucial to making the scheme work.
"We have to stop as a State or as a local authority looking at land as a commodity. We have to look at it as resource. If we look at it as a commodity we will always be looking for the best price. If we are looking at it as a resource we say 'how can it best be used'?, whether it is for housing, or hospitals or schools or whatever".
He also proposed that the 20% of IDA land be set aside for affordable housing, pointing out that this could meet the housing demands of employees of the companies the agency is seeking to attract.