In Dublin, McGrath's principal concern was the restoration of Dublin Castle, which started in the late 1950s and continued for decades. Among the buildings he designed was the Royal Hibernian Academy, RHA, building in Ely Place, Dublin. He had been appointed an associate member of the RHA in 1949 and became a full member in 1967. The following year he became the Academy's professor of Architecture. For many years, starting in 1946, McGrath championed and worked on the design for a National Concert Hall for Ireland which was to be built at Raheny. However the project was always dogged by political complications and was eventually cancelled in 1973. McGrath died in Dublin a few years later in 1977, at the age of 74.
