The new roof tiles would be arranged according to the original colour pattern, which had been identified through photographs in the Hocken Library, university property services officials said.
University staff had closely consulted the Historic Places Trust regarding the restoration, officials added.
The reroofing stage was expected to be completed about July-August, and replacement painted plastic downpipes were to be installed.
Regular maintenance had occurred through the years, but this was one of the larger restoration projects involving the professorial houses since the original brickwork was plastered over in the 1950s, officials said.
The houses were among the buildings designed for the university by architect and engineer Maxwell Bury, and were built in 1879.
Painting of windows and doors at the two professorial house buildings, located north of the university clocktower complex, started in February this year, and is expected to continue for about another two months.
Some rotten wood will also be removed and replaced.
Historic plasterwork will also be repaired and restored.