Several years ago I came across this map which shows the year of construction of every building in the Netherlands. It was impressive how one can import such a large dataset and make a soothing and clear map covering the whole country.
Then I decide to do one for Vancouver. Why not the whole of Canada? Considering the vastness of the country, it is difficult to collect all the data from coast to coast to coast, let alone my computer processing all the building polygons.
From red being the oldest to blue being the most recent, the map above gives a brief idea on how old is your neighbourhood. With the full resolution, you can see from buildings to buildings on how old they actually are.
Update: I recently came across this project by Statistics Canada which contains the building footprints from 2019 in Canada. The open data can be useful to keep the project up-to-date.