Finally! I have found an identity for this mysterious house on Mississauga Road. Apparently, this Italianate/Second Empire-style house used to belong to the Garrett S. Fuller family. It was then converted into apartments until it was abandoned( There are rumors that a murder occurred here, and it's haunted). I found a sketch of the house from 1877 and it had a mansard roof, which has since been replaced,and the additions covered in siding. Until recently, it had a gate and no-trespassing signs, but they have since been removed, although active construction workers are constantly around the property. There are also two other abandoned properites, an early 1920s bungalow right beside it and set back from the road, a large, block-shaped house.
There is a bit of information on this house in a Brampton Heritage Assessment report.If you would like to read it, just click on the link below.
(note the coordinates do not lead exactly to the house. Turn the view in all directions until you notice a tall house.THAT is the house, the exact address is 8472 Mississauga Road.)
The link below gives some background on the plot itself, and is titled:
2.2 East Half of Lot 3, Concession 5 WHS, Chinguacousy Township