Elphinstone Park, Adyar, a property of about 158 acres with a large building was bought on 1 July 1885 and the home for the boys was transferred there the same day.
During World War II, the Institution was shifted to the Coimbatore Government Arts College till June 1946.
The construction was started on 17 March 1913, St Patrick's Feast Day and was completed in 1915 at a total cost of Rs.
Many past pupils of the school held positions of responsibility and trust in government offices and in private business firms.
Many brought credit to their school by deeds of bravery in both World Wars, and some entered Seminaries and Novitiates of Religious Orders.
The physical training given bore fruit when two past pupils were in the Team that represented India in the Olympic Games in Amsterdam in 1928.
In January 1931, Mr. Bambridge, Director, M/s Binny & Company, Madras, presented to the school the "ROYAL HUMANE SOCIETY'S MEDAL" and certificate which had been awarded posthumously to Mr. Martin.
In the early 50s the vast school land was sold to Gandhinagar Housing Society and the present Gandhi Nagar Colony came up.
The number of boarders also reduced after India gained independence due to emigration to Australia and Great Britain.
The year 1991 saw the completion of a three-year massive renovation of the oldest building and it was dedicated to all the old students of St. Patrick's on 17 March 1991.
This was followed by a cultural programme and dinner for special invitees which included the staff of St. Patrick's and St. Michael's, priests and religious members of nearby parishes and communities.