The budget for Dublin’s College Green civic plaza has soared to €80 million, an increase of €70 million since the scheme was last submitted for planning permission eight years ago.

The project to create a traffic-free plaza is also facing additional lengthy delays with completion unlikely before the end of this decade, Dublin City Council officials have said.

In May 2017 the council submitted an application to An Bord Pleanála for a €10 million pedestrian and cycle plaza. In November 2018 the board refused permission citing the potential for “significantly negative impacts” on bus services.

The National Transport Authority (NTA) in September 2020 published its final plans for a redesigned bus network for the city. Under BusConnects, services would be routed away from College Green and east Dame Street.

With the conflict with bus services removed, the council decided to double the size of the plaza. Traffic would be banned from the area west of the Luas lines in front of Trinity College, extending as far as the junction with Dame Street and South Great George’s Street.

Architect image of the proposed new College Green plaza

Under BusConnects, bus services will be routed away from the College Green area. Photograph: Dara Mac Donaill

Two years later the council announced a new design team was required due to increases in the scope of the project.

In a briefing to councillors in recent weeks, the scheme’s project manager Marie Gavin said she hoped “preliminary designs” would be completed by the end of the summer. These designs would then be subject to a “screening process” to determine whether the project could be progressed through the council’s internal planning system or if an application to An Coimisiún Pleanála, the new name for the reconstituted An Bord Pleanála, was required.

Cost was “a big factor” she said. “It is a big project so it’s going to cost a lot of money.”

The project had been approved for a budget of “about €80 million” that would be part funded by the NTA. That included a “huge contingency fee” of “about 40 per cent” but that should “hopefully cover everything we have to do” she said.

The timeline for the project would depend on whether an application to the Coimisiún was required, which would add “at least 12 months, minimum” but also on the removal of the bus routes, now scheduled to happen by the end of 2026.

“Realistically we’re looking at about October/ November 2027 to be on site with the project, with the best will in the world, and then it could be up to a three-year construction period.”

A spokesman for the NTA said it expected to complete rerouting of buses from the plaza area by the end of next year. The NTA will make a contribution to the cost of the project, but the level of that contribution has not yet been determined, he said.