Developer Michael O'Flynn has claimed builders would be unable to deliver affordable homes in some locations even if given free land, because a host of costs would still push prices past what buyers can afford.
Affordability needed to be "urgently looked at", he said, including the shortfall between what buyers can pay and housing input costs including the price of land, levies and Vat.
"We need public-private collaboration, the private sector is the only sector that can deliver housing quickly. There is no hope in dealing with the current situation unless we face up to this, we [currently] have an unaffordable product," he said during a PwC Construction Industry webinar.
The property developer, among the country's biggest housebuilders, hit out at promises to ramp up housing delivery unless affordability is addressed.
He said he was "surprised" when he sees "tens of thousands of houses" being proposed without any strategy as to how they might be delivered and no acknowledgement of the fact there is affordability on one side and viability on the other.
He also called for transparency around the cost of public housing, where he said there is a perception that costs are less than what they actually are.
"You need to do a cost-benefit analyst of social housing. Any housing that is being proposed under social schemes or under the Land Development Agency - there should be costing of those schemes to go with the plan," Mr O'Flynn said.
He added that he did not think "people appreciate how efficient the private housing industry is given the regulations".
Mr O'Flynn - whose company recently completed housing developments at Rokeby Park, Lucan, Co Dublin and Rochestown in Cork - said innovative ways to bring land to the market in a more affordable manner needed to be looked at.
A Vat holiday or Vat reduction and shared ownership schemes between the Government and home buyers also needed to be examined, he said.