It opened in September 1933, when it was used initially as accommodation for those priests who had, until that time, lived at addresses on the adjacent College Row, close by the school gates. The College Chapel was finished in 1952 during the presidency of the Rev. McLoone. The chapel was designed by J. J. Robinson, architect of Galway Cathedral, and completed in 1961 at a cost of £42,000. The outline of a subterranean toilet block parallel to the College Chapel, which was used until the mid-1930s, can still be seen today. On Saturday 21 October 2017, the class of 1962–67 (featuring future Member of Cabinet Jim McDaid) held a reunion at the College, which began with a service in the College Chapel to remember the eight who were absent due to death. Two science laboratories and a demonstration room were added in 1964 during the presidency of the Rev. Dr. Daniel J. Cunnea, who was schooled in, and took an interest in, science and mathematics. Work got underway on a further extension to the College in 1977 during the presidency of the Rev. Laverty. Work concluded in 1979, and the "New Building" was inaugurated in 1981 — the 75th anniversary of the College's foundation. The Rev. O'Fearrai created the College Library by converting the remnants of the boarding facilities after this wing closed in 1992. Early 21st-century efforts to attempt a further extension proved fruitless. Two plans were drawn up, but an approach was never finished. As per planning regulations, the school installed a set of ramps and two chair-lifts. To serve first-year students, three prefabs were installed in summer 2008; these were followed by four ancillary prefabs in summer 2010. The first playing field opposite the College was completed during the presidency of the Rev. McLoone. On 3 May 2019, the Minister with Responsibility for Defence Paul Kehoe and Chief of Staff of the Defence Forces Vice Admiral Mark Mellett reviewed 114th Infantry Battalion on the playing fields at the College in advance of its UNIFIL deployment to Southern Lebanon, Ireland's largest overseas mission to date. The College was selected in recognition of County Donegal providing the largest contingent of troops to the mission (many of the rest came from Dublin and other Leinster counties). The ceremony included a parading of the unit colours (flag), a speech by Kehoe and a ceremonial "march past". Minister for Education Joe McHugh, in whose constituency the event took place, was among other dignitaries in attendance.