28 Armagh Street
The first school location was at 28 Armagh Street, which opened on 8th February 1910. Students from all over the country enrolled at SMC. When the school roll increased, the school needed to expand. The kindergarten class was held in a classroom that was converted from an old stable. The primary school classrooms were in the Old Deanery in Cranmer Square. The school has always had a chapel which is an important feature as the school values are based on the Anglican values.The chapel use to be very small and hot, often a girl would faint and had to be passed along the floor to get her out.
Bishop Julius opened a new school site on the 10th June 1914. The building was brand new and had state of the art lighting, heating, offices, classrooms, ventilation and tennis & basketball courts. St Margaret's was registered as a Primary and Secondary school in 1921. In April that year the school roll reached 200 students. In 1926 the school roll had risen to 238 students and this put strain on the boarding establishments at Armagh Street.
89 Papanui Road
For a while in the early 1920's, St Margaret's ran a small school called "Little St Margaret's". It was a preparatory school that catered from kindergarten to Year 5. It was held in the St. Mary's Sunday school in Merivale. However the school was sold due to students finishing and moving to Rangi Ruru instead of St Margaret's College.
In the 1940's, the school roll was growing and the solution was found by moving the school to the current Papanui Road site. In 1959 the whole school finally moved to Papanui Road. Over the years, buildings such as the Molly Mullan (1978), the Jean Crosher Wing (1980) and the new Science and Technology building (1999) were opened.