The 17-storey Exo building at Point Village in the docklands is Dublin’s tallest office block, complete with its eponymous exoskeleton steel façade and a glass box restaurant and bar. It was developed by Grant Thornton receivers and Nama and designed by Shay Cleary Architects, with funds managed by Tristan Capital Partners in London. An Post is the anchor tenant, having relocated its headquarters from the GPO. Other firms letting the property include tech companies Ancestry and Yahoo. But three years after the offices opened for business, alleged problems that arose during the build are being litigated.  In what could be…