Whitecastle Developments is to begin work next month on a mixed office and apartments scheme at the site of the old Olympic Ballroom in Dublin. An Bord Pleanβla has approved the scheme, which will have 12,000 sq ft of offices and eight apartments, one of them a three-bed penthouse with a wrap-around terrace of 1,000 sq ft. Whitecastle, which is controlled by Phil Monahan and Declan O'Donnell, paid £2.5 million (3.7m) for the ballroom.