Mr Tennant and Mr McCann plan to appoint a contractor to build the 73m structure, which could house up to 2,000 office workers once it is completed.
Roland O’Connell of Savills said the property company – which is agent for the building along with CBRE – would begin the search for potential tenants now that construction had moved a step closer.
“We will be out pounding the pavement,” Mr O’Connell said. He added that Savills has had “some conversations” with companies in the market for offices in Dublin.
Construction will take two years, which is generally the lead-in time required to secure larger companies.
Mr O’Connell is expecting that Brexit could draw more commercial tenants to Dublin, but argues that it is the icing on the cake, as the capital’s office market is already strong.
The Irish Times reported on Wednesday that developer Johnny Ronan, now well out of Nama, is lodging plans to build the tallest building in Dublin on a site adjoining Tara Street railway station, topped by a restaurant and bar with panoramic views over the city.
The proposed tower would be higher than the Exo, rising to a height of 88m (nearly 290ft), compared to 59m (194ft) for Liberty Hall, just across the river Liffey, which was Dublin’s tallest building for decades until it was outstripped by Monte Vetro, the Google HQ in Grand Canal Dock, at 67m.