John Sisk and Son has confirmed a single case of the virus at the TU Dublin development at Grangegorman.
The site in north Dublin has been shut down for deep cleaning.
It comes after the confirmation of an outbreak elsewhere on Monday, when more than 20 workers at a site on Townsend Street also tested positive for the virus.
Initially one staff member at the Townsend Street site was found to have the virus, later resulting in more than 20 workers contracting it.
