[someone123]

I'm guessing that by 1990 or so, Toronto and Halifax had roughly equal proportions of heritage buildings to modern buildings, though the heritage buildings in Halifax tend to be much older and of a much higher quality for the same period until sometime near the end of the 1800s.

The top-notch heritage buildings in Halifax don't really have equals in Canada outside of Montreal and Quebec City. Even then there are often no equivalents in terms quality (e.g. Province House) and the styles of all buildings are unique to the Maritimes (Saint John has many similar buildings of a similar quality from around the mid-1880s to the early 20th century), at least within Canada.

The big caveat for Halifax is that there are very few areas along the lines of "old" Quebec and Montreal. This is largely why I don't subscribe to the idea that the downtown should be fully preserved - only half of it is left to begin with!