There are 600 empty sites in the capital according to an audit by Dublin City Council.
The Mayor of Dublin is calling on the government to impose a levy on people who hoard the zoned land land within the city centre.
Oisin Quinn says the levy proposal would be designed to encourage owners to make use of the building or site to help alleviate the lack of supply of housing in Dublin.
And he says the issue needs to be addressed now to avoid a property bubble: