The John Irwin House is named on the City of Toronto's registry of historic properties.It is one of the oldest surviving residential buildings in its neighbourhood.The city describes the house as being an example of "Second Empire" style.The house is located at 21 Grenville Street.That part of the city, east of Queen's Park, was opened for residential development in 1860, and the house was recorded on city records as being owned by John Irwin in 1873. Enzo di Matteo, writing in Now included the house in a profile of 15 historic properties that were nevertheless under threat of demolition.