The Dublin Airport Authority (DAA) plans to spend €450 million on the existing airport terminal where Ryanair will be based in future, a conference was told yesterday.

Despite concerted opposition to most of its proposals from Ryanair, the DAA has committed to expenditure of €450 million on Terminal 1, which is currently used by all passengers. Aer Lingus will move to the new Terminal 2 building. A planning decision on this building is expected today from Fingal County Council. Approval may be granted, but it could come with conditions.

Addressing the "Towards Sustainable Airport Development" conference in Dublin, Declan Collier, the chief executive of the DAA, said that a range of projects were being planned for Terminal 1, in addition to the construction of Terminal 2. These included a basement area for additional check-in desks, Pier D, apron works, a Pier A extension, retail upgrades and a reconfigured check-in and security area. The most significant item will be Pier D, which will cost €120 million.

Mr Collier said that the old terminal would be dedicated to low-cost traffic and planes using this part of the airport would have ease of access to the northern runway. He said that this terminal would have capacity of more than 15 million at a "comfortable level of service".

While Mr Collier avoided directly challenging points made at the conference on Monday by Ryanair's chief executive, Michael O'Leary, he did say that check-in areas would be needed at Terminal 2. This contradicts an assertion by Mr O'Leary that in future passengers will do their check-in online and simply drop their bags off when arriving at the airport. Mr Collier said that most long-haul passengers would continue to use the traditional check-in.

Mr Collier also defended the 9,000 square metres of retail development in Terminal 2, saying that it would help to subsidise airport charges.