State bad-bank Nama controls enough land to build at least 80,000 homes - but large parts of its portfolio cannot be developed.
New figures show that Nama debtors and receivers control some 2,806 hectares of land across 22 counties. More than 60pc is in the high-demand areas of Dublin, Kildare, Meath and Wicklow.
But sources said there were "substantial barriers" to development both within the capital and across the country.
Much of the land cannot be developed over the next five years unless there is "substantial progress" and essential services including roads, sewerage, public transport and schools delivered.
The failure of the main political parties to form a government over the past six weeks means that decisions around funding the capital works required have effectively been put on the long finger.
In Dublin, the lack of infrastructure including roads and water were "major issues" in areas where development might otherwise be economically viable, sources said.
Unless the works are completed, the land will effectively remain sterile for the foreseeable future.
The data comes as figures from the Central Statistics Office (CSO) show that while the number of homes being approved has increased, it is still way below the level needed to meet demand.
Planning permission was granted for just over 13,000 new homes last year - a 76pc increase, but far short of the 25,000 units needed.
In all, some 13,044 homes were approved, of which 6,658 are in estates (up 89pc), 3,592 are one-off (up 16pc) and 2,794 are apartments (up 256pc).
In the last quarter of 2015, permissions were up 95pc compared with the corresponding period of 2014.
While there has been a pick-up in house-building activity, it is still at very low levels. Last year, less than 13,000 units were completed.
Nama has pledged to deliver 20,000 new homes out to 2020, but has sufficient land under its control to build far more.
Residential density guidelines from the Department of the Environment suggest a minimum of 30 and 50 units are built per hectare in urban areas. The upper limit is recommended in areas with good transport links.
This means the land could yield between 84,000 and 140,000 homes.
However, sources said that some cannot be developed.
"In some areas within Dublin and the wider Dublin area, development remains unviable for commercial, planning and infrastructural reasons, with the latter being a major issue in certain areas," one said.
"Much of the development land within Nama's portfolio outside the major urban areas is unlikely to be viable within the next five years without substantial progress by public authorities in terms of putting in place the necessary planning frameworks and addressing public infrastructure deficits."
The biggest landholding is in Dublin at 1,173 hectares, around 42pc of the total.
It is followed by Cork (620ha) Wicklow (240ha), Kildare (204ha) and Limerick (115ha).
Six hectares or less are controlled in Leitrim, Clare, Monaghan, Roscommon, Sligo and Donegal. Nama debtors and receivers have no land in Longford, Cavan, Kerry or Tipperary.
Separately, figures also show that Nama has 700 residential units for sale, with 3,300 under construction. Permission is in place for 4,800, another 4,300 are in the planning system and applications will be lodged for a further 7,237 units (5,800 in Dublin) over the next 12 months.