During the 1930 Rangoon earthquake, St. Mary's Cathedral suffered little damage and it withstood the Japanese invasion during World War II.

[6] For some time before his death, Paul Bigandet MEP (1856–1894), Vicar Apostolic of Burma, started planning of a new and larger cathedral, as the Catholic community in the city was growing.

A suitable piece of land measuring over fifteen acres east of St. Paul's High School was found, and the Bishop submitted an application to the Government of Burma, asking permission to sell, as a freehold, the site of the old cathedral, with a view to the proceeds being entirely applied towards the expenditure of erecting the new cathedral.

"[attribution needed] The Bishop in his reply pointed out that his plea to sell the site of the old cathedral was based on similar concessions made by the government, only a few years previously, to other Christian communities.

Two months later, on 23 January 1893, the French Bishop was informed that the Government of India sanctioned the proposal to sell the site of the cathedral in Barr Street and to appropriate the proceeds for the erection of a new one.

Father Janzen had studied in the "École Polytechnique" under Dr. Pierre Cuypers, a Dutch architect, who designed many of the catholic churches built in the Netherlands, as well as the Rijksmuseum at Amsterdam.

Bishop Cardot prevailed upon the Superiors of the Paris Foreign Missions Society to allow Father Janzen to accompany him back to Rangoon.

Father Janzen went to his native Netherlands to consult his old classmate, Dr. Cuypers Jr. who prepared a new plan for a French Catholic Cathedral in Neo-Gothic style.

As a basis, a layer of sand nine feet in depth was substituted for pyinkado piles while an additional hundred of the latter was driven down to strengthen and support the rest.

Never tired of training and directing his subordinates, he simplified their labor by providing them with wooden rules, frames, and other devices to render their operations more mechanical and exact.

Father Janzen sawed through the connection between the towers and the rest of the edifice from top to bottom so as not to damage the main structure.

Father Janzen lives hidden away in his single room in the ground floor having but the plainest technical apparatus, restricted to very scant funds, and quite uncertain as to the future.

For many months, he has been deprived of the consolation of celebrating Mass, on account of a fractured limb, which no longer serves for standing at the altar.

Yet, the Cathedral works and keeps going; designs are forthcoming as required by each detail of workmanship; expedients for overcoming difficulties and for accommodating disarrangement are invented; and many curses, which have nonplussed professional skill in Burma, have been successfully dealt with by the wonderful spirit that dwells in the dying and broken body of this devoted priest."