He won the competition in 1873 [2] to design the Basilica of the Sacré Cœur on Montmartre in Paris, and saw construction commence on it, though he died long before its completion in 1914.
[4] As attaché to the commission for historical monuments, he participated in the architectural rediscovery of the Middle Ages, touring and studying medieval sites intensively.
In 1873 his entry in the competition for the construction of a basilica on Montmartre, a hill dominating Paris, was selected ahead of 12 other submissions, by Cardinal Joseph Guibert.
The work of Paul Abadie was not appreciated by some academics in the mid-twentieth century, as they felt he was fanciful, destroyed much Romanesque heritage, and had no compunction about adding whimsical sculptures of his own manufacture on capitals and corbels.
[10] Many communities in the present-day Charente and Dordogne departments are indebted to him for the restoration of a large number of ecclesiastical buildings, many that were in severe disrepair or simply neglected over centuries, for example in Angoulême, Périgueux, and Cahors, where from 1849 onwards he was the diocesan architect for those dioceses.
He also inspired a large number of churches, most notably in Paris (Saint-Esprit, 1928–1935, by Paul Tournon; Saint-Pierre-de-Chaillot, 1931–1938, by Émile Bois; and Sainte-Odile, 1934–1946, by Jacques Barge).