Large swathes of a major new redevelopment of the Grangegorman campus in north Dublin have yet to receive formal funding commitments from the government while the overall cost of the project is not known.

Despite a high-profile launch by Taoiseach Brian Cowen last Tuesday – where guests were provided with a detailed rundown of the plans for the entire project – it has also emerged that parts may also be delayed.

This would occur if some 21 buildings owned or occupied by DIT do not raise a "conservative" target of €158m when they are put on the property market from the start of 2013.

The project – which Cowen described at last week's launch as "a central piece of national economic infrastructure" – is divided into a number of "tranches".

"Each tranche will only be developed as the funding becomes available," a spokesman for the Grangegorman Development Agency told the Sunday Tribune. "The funding is currently available for the development of DIT Tranche 1 and HSE Tranche 1."

This funding relates to the provision of core DIT educational facilities at a cost of some €496m – of which €212m or equivalent has been sanctioned by government – as well as €60m worth of HSE-funded replacement accommodation for residents of St Brendan's hospital and new local clinical services. But it does not include the three further tranches, covering the relocation of DIT's engineering faculty to the site, student accommodation, sports and recreational facilities, a dedicated research space, and community-related facilities such as a primary school, a public library, and elderly housing and disability services.

The GDA could not provide an overall cost for the entire project, estimated at €1.5bn in the An Bord Snip Nua report.