The BMS building, as it is presently known, was built in two phases. The first between 1849 and 1875, the second between 1875 and 1907. The building is constructed of coursed rubble limestone walls with eliptical arch opennings for carriages. top round headed windows, and covered with double pitch roofs, in six short bays on the North side, and three long bays on the south.  Last year Irish Rail decided to relocate 220 staff of the Infrastructure Department. This building was chosen out of a number shown to the Chief Architect. It is located on a Railway Engineering site and was falling into desrepair. About ten staff repairing bus and train upholstery seats were occupying the building.  The redevelopment consisted of adding mezzanine floors in alternate bays, creating double height inner coutyard spaces which bring natural ventilation to the inner offices, and single and double height open plan and cellular spaces all lit by apex rooflights. Consideration was taken to limit to a minimum any modification to the original buildings. All the original trusses, cast iron beams and windows, and stonework where restored.