The launch of DIT's new Grangegorman campus will be delayed by two years following a failed legal challenge by an under-bidder to design and build part of the project.
The campus had been due to become home to about 10,000 students this September, coinciding with the arrival of the new Luas Cross City line, which will stop at its gate.
However, a challenge was lodged in relation to a contract, worth up to €200m, to design and build its two main teaching blocks.
The contract for the structures - the Central Quad and the East Quad - was awarded in February 2015 to a company called Eriugena.
An unsuccessful tenderer, the Dutch-based BAM PPP, challenged the decision and took a case against the National Development Finance Agency (NDFA) and the Minister for Education.
The NDFA is the statutory body charged with procuring public private partnership (PPP) projects in Ireland on behalf of the public sector.
In the case of Grangegorman, it has been acting on behalf of the Minister for Education.
While the commercial wing of the High Court dismissed the case late last year, work on the Central Quad and East Quad could not go ahead while the action was ongoing.
Now, a two-year delay is certain to mean that the final price tag for the total project will rise above the original estimate of €485.5m.
The NDFA has been working with the successful tenderer with a view to finalising the financial end of the deal and September 2019 has been set as the new target date for the opening.
DIT, which caters for 10pc of all third-level student in Ireland, is currently spread across up to 40 buildings around the city.
The move to Grangegorman, on the northside of Dublin city, was supposed to unify the college's 15 schools and other facilities on a single site for the first time.
The development of the new campus and some other community facilities, has been a phased project, originally due for final completion in the year 2020.
In September 2014, about 1,200 students from art, design, photography and social sciences, along with 200 staff, moved into refurbished buildings on the campus, formerly home to St Brendan's Hospital.
Last month a new DIT innovation hub, Greenway, opened on the 73-acre site, its first new building with five storeys.
But the completion of the Central Quad and East Quad will bring the main body of students to Grangegorman, catering for those currently located in DIT colleges in Cathal Brugha Street, Rathmines and Kevin Street.
That will be followed by the development of teaching space for business students currently in DIT Aungier Street, a library and student accommodation.