The Municipal Property Assessment Corporation (MPAC) maintains records that include the age of a house. This information is only released to the owner of the property.
How do I trace my family history?
The two best places to start the search for your family's history are the Archives of Ontario and the Toronto Public Library which holds two major genealogical collections at the Toronto Reference Library and the North York Central Library which also houses the resources of the Ontario Genealogical Society. If you are looking for more recent birth (for the past 95 years) marriage (for the past 80 years) and death records (for the past 70 years, you should contact the Office of the Registrar General.
Where can I find old photographs, maps, and historical documents on Toronto?
The City of Toronto Archives, the repository for Toronto's historical records is located near two of the City's most popular heritage sites, Casa Loma and Spadina House, and just one block north of the Dupont subway station.