Sinn Féin has pledged to deliver 50,000 affordable homes over five years if elected to government.
Party leader Mary Lou McDonald said the target was achievable as she unveiled a new policy document on Thursday.
Sinn Féin said it would also deliver 75,000 social homes in the same period.
It says the plan will see the State fund the delivery of 50,000 affordable homes through local authorities, approved housing bodies (AHBs) and community housing trusts – at a cost of €13.2 billion.
That figure comes from 6.9 billion euro in voted Exchequer funding as well as €6.3 billion in borrowing by local authorities and AHBs from the Housing Finance Agency and other sources.
Sinn Féin said the homes will be available to buy for prices between €250,000 and €300,000, or to rent at or below €1,000 per month.
Along with price, Sinn Féin said the difference in its plan and the Government’s is the “scale of ambition”.
For comparison, the Government delivered more than 4,000 affordable housing options last year.
Ms McDonald said the coalition was delivering “unaffordable homes” at a cost of up to €500,000 or €1,800 per month in rent.
The 50,000 figure breaks down to 25,000 one-to-three bedroom homes to buy for households with mortgage approval, a gross household income of up to €90,000, do not own a home at time of purchase and whose savings are insufficient to purchase a home on the open market.
It said that affordable cost rental should be no more than 33 per cent of net income and that mortgages in affordable purchase should also be less than a third of net disposable income.
Sinn Féin said it can achieve a lower price by separating the cost of land and site servicing from the cost of building the home.
In essence, the State would for all land related costs and retain ownership of the land while the purchaser pays the price of construction.
It would mean the householder would own the home but not the land, but would be able to sell the property on at an affordable rate.
Sinn Féin also plans to deliver 25,000 similar size homes for households with a net income of up to €66,000 in Dublin and €59,000 outside of the capital.
Speaking to reporters for the launch of the document on Thursday, Ms McDonald said: “We have the finance, the land and the builders to solve this crisis, what is needed is the right plan – and Sinn Féin has that plan.”
She added: “People that don’t have time out to wait any longer. We’re in a situation of real stress and crisis in people’s lives and that needs to be addressed.
“A core component of that is those people who earn too much to qualify for social or council housing – if there was council housing – and those who are completely priced out currently of having any prospect of purchasing their home.
“And indeed those people who will struggle and are struggling hard to afford rent, who have been promised affordable rental and close rental homes and it hasn’t materialised.”
Sinn Féin housing spokesman Eoin O Broin took aim at current Housing Minister Darragh O’Brien’s response to the opposition party’s policy platform.
He said: “Given that homelessness is at the highest levels in the modern history of the State, that house prices and rents are higher than they’ve ever been before and that he misses every single target of his own, he would spend his time doing his job and not wasting his officials time emailing me for political stunts.
“This is too serious for the kind of nonsense that we get from Darragh. Darragh should do his job. He’s had four years, and he’s showed he can’t, he’s failed.
“That’s why we’re setting out a clear and radical alternative, so people can make up their minds.”
Mr Ó Broin also said that increased delivery of affordable homes would have a moderating effect on house prices in the open market, but said that impact would be over a long term and unpredictable.
Mr O’Brien said the Sinn Féin document is “really very weak”.
In a statement, he said: “There was absolutely no detail in it and a complete failure to answer even basic questions. What we do know from it is that the ‘affordable leasehold purchase scheme’ is not home ownership, and worse still, they have not confirmed with commercial lenders that it’s actually possible.
“As well as that, it’s an exclusionary scheme. A Garda and a teacher on point five of their respective salary scales would not be eligible for apply for these homes. Unlike the Government schemes which contain no arbitrary salary caps.”
“It’s clear from this document that the Sinn Féin ‘alternative homes plan’ is built on foundations of sand,” he concluded.
Sinn Féin said it would publish its full five-year housing plan in September.
