With the construction of the sandstone boundary walls in 1905 and the substantial clearing of the native vegetation, the St Patrick’s Estate still retains its historical and visual relationship with North Head.
In 1914, a bill was passed through the New South Wales Parliament, known as the St Patrick’s College (Manly) Bill, allowing for the subdivision of approximately 21 acres running down to and overlooking Shelly Beach and Fairy Bower’ to help meet the upkeep of College costs. As noted in an advertisement in the Sydney Morning Herald (20 March 1915), allotments were offered on a 99 year leasehold basis on 27 March 1915.
Leaving aside developments in the sub-division, no further building activity seems to have occurred on the grounds until the 1930s, when substantial post World War II developments took place on the Estate. Kelly House was built in 1954 for residential purposes, a swimming pool made of reinforced concrete was begun at the end of 1956 and opened on 17 November 1957. Gilroy House was opened in 1961, a brick addition was made to the Convent around 1961 and St Paul’s Catholic College was opened in 1965, with further buildings added in the late 1970s.
The last alteration to the physical dimensions of the property was made in 1975, when a 25 – 30m foreshore area of the Estate at Spring Cove was donated by the Church to Manly Council, providing a public walkway connecting Little Manly Point to Spring Cove. A block wall consistent in height with Estate stone walls was constructed on the new site boundary.
From 1995 to 1997 various Development Applications for the residential development of four parcels of land zoned residential by Manly Council’s Local Environmental Plan (LEP) 1988 were approved.
In 2001 construction of Bear Cottage, a children’s hospice in the grounds of the Estate adjacent to Fairy Bower Road, was completed and the facility was officially opened.
The residential developments known as College Green & College Court were completed in 2002; Cerretti Crescent was completed in 2007; with Montpelier Place completed in 2014. Spring Cove commenced construction during 2013.