Hans Blumenfeld was born in Osnabruck, Germany in 1892 and grew up in Hamburg.  Although he was expected to follow the family banking tradition, Hans wanted to be an architect and worked as a carpenter’s apprentice.  In 1914, he enlisted in the German army in World War I and this experiences confirmed his lifetime activist leanings.  After, Hans continued his studies, finishing his master’s thesis, which had kindled his interest in the relationship between the form and function of cities.  He describes the period from 1921 to 1930 as becoming a journeyman architect.  He entered the US through Ellis Island in 1924 and worked as a draftsman in New York and Baltimore and, finally as a designer in Los Angeles, then worked back in Hamburg and Vienna. 
Has joined the Russian State Planning Institute in1930.  Here he embarked on his first real city planning—general plans of Vladimir and Kirov.  Blumenfeld left the USSR in 1937, returning to the US and getting a job as a research assistant for the Philadelphia Housing Association and eventually joining Philadelphia's City Planning Commission in 1945.  His work in Philadelphia was interrupted by a short term return to Germany in 1949, during which he advised the United States Military government about future German city planning.  The US State Department refused to renew his passport during the McCarthy era and he came to Canada in 1955 as assistant director of the Metropolitan Toronto Planning Board where he was instrumental in shaping Toronto and its hinterland through the 1959 Official Plan for land use, housing, and transportation.
He resigned at the mandatory retirement age of 70 and became a private consultant working for clients like the cities of Montréal, Toronto, and Vancouver, and for 14 years with the National Capital Commission in Ottawa.  Hans became a professor at the University of Toronto, where he taught well into his eighties, and at the University of Montreal.  He was the author of numerous acclaimed articles and books, including The Modern Metropolis (1967) and Metropolis and Beyond (1979).  His most significant contribution was his vision of the ‘metropolis’ as a new urban organism whose unique scale and structure require diagnosis and treatment.
Acknowledged as having an extraordinary intellectual range, Professor Blumenfeld was a leading figure in 20th century urban and regional planning.  He was a recipient of the American Institute of Planners' Distinguished Service Award and received honorary doctorates from the University of Montreal, University of Waterloo, and Technical University of Nova Scotia.  In 1978, he received the Order of Canada.  His autobiography, Life Begins at 65: The Entirely Candid Autobiography of a Drifter, was published in 1986.  In it he talks of planning:  “I do not know of a better recipe for a happy life.  I consider myself highly privileged to be one of the fortunate few able to follow it.”
At the age of 90, he was the chairman of the Toronto Coalition for Peace.  Hans passed away at Toronto in 1988.