Hundreds of acres of back gardens and laneways in Dublin should be freed up for housing development, a lobby group has claimed.
The Irish Home Builders' Association says the use of "idle" gardens and lanes would be one way to address the severe shortage of housing in the capital.
It also called for State lands, such as Cathal Brugha Barracks, Rathmines, Dublin, to be made available for social and affordable housing.
The IHBA is a Construction Industry Federation group which represents house-builders, and highlights issues facing the sector.
In a statement calling for new and innovative ways to tackle the shortage of housing, it said there was an urgent need to maximise land use within the city's boundaries.
"It is not inevitable that Dublin should develop like an octopus stretching its tentacles into every Leinster town and village," it said.
"There is a critical need to review existing use of land within the M50 with a view to containing the footprint of Dublin."
With demand for new houses outstripping supply by a ratio of nearly two to one, there was a critical need for more zoned and serviced lands in the right locations, the association said.
It had for some time been raising the idea that large tracts of State land could be utilised to address supply inadequacies.
"For example, does it make sense for the Army to have a barracks in Rathmines covering 40 acres? Should they not move to the Curragh and open up that land for a mixed development scheme?
"The planned release of such lands on to the development market would facilitate an enhanced supply of zoned and serviced land for social and affordable housing and, thereby, provide housing to some of the 20,000 families now on the housing list for local authority housing in the Dublin area," it said.
The statement added that all around the city there were "possibly hundreds" of acres of land lying idle in back gardens and laneways.
"The time has come for a new planning initiative. Much of this land should be opened up for new well-planned developments.
"Higher densities of population lead to much more efficient use of resources, particularly public services and utilities," the statement said.
"The American model of lower-density suburban sprawl being pursued in Ireland is in turn handcuffing us to the motor car and high-energy consumption levels, a model of development which has a huge downside risk for the whole country."
The association called for policy-makers, planners, architects and designers to "put their heads together" with builders to plan for the future housing needs "in a more thoughtful, coherent way".