An oral hearing into plans for a major redevelopment of RTE's Donnybrook campus has heard that the realisation of 'Project 2025' is necessary if the national broadcaster is to meet the demands of the digital and high-definition age.

Under the proposal, all of RTÉ's services would be housed in one purpose-built complex, which would include five new TV studios and a public plaza.

Construction of the new campus would take place in five separate phases over a ten-year period.

Planning permission for 'Project 2025' was granted by Dublin City Council last April.

However, An Bord Pleanála decided to hold an oral hearing following receipt of a number of objections to the proposal.

Several witnesses representing RTÉ gave presentations to the hearing on the first day.

Director General Cathal Goan said the broadcaster currently has an average daily TV viewership of 2.5m.

Mr Goan said that 1.4m people listen to RTÉ Radio every day and that its Online services are accessed on a daily basis by over 300,000 users.

He said that RTÉ had reached a point 'when it can no longer continue economically to re-engineer or add to its existing facilities'.

Mr Goan added: 'To remain competitive and to continue to give Irish viewers, listeners and web users the best possible services, we (RTÉ) now have to invest in new facilities built to meet the demands of the digital age.'

RTÉ's Chief Financial Officer Conor Hayes told the hearing that 'differing pressures arising from new technology and increased competition, along with the developments in services' was putting excessive strain on RTÉ's existing building fabric, 'which already suffers from a degree of age-related deterioration'.

The hearing is due to continue until Friday and An Bord Pleanála is expected to give a decision in relation to full planning permission by the end of this year.