Located at the north-east corner of Fennel Avenue and West 5th Street, the four-hectare walled property exemplifies the Picturesque movement of design with the architecture and landscape forming a coherent whole. The property's placement atop the escarpment, the informal arrangement of plantings, and vestiges of a long, tree lined driveway contribute to this Picturesque character.

Contributing to the context of the property are limestone structures and improvements such as a carriage house, a dovecote with lancet windows, and a high, buttressed wall enclosing parts of the property and garden.

Auchmar was the estate of Isaac Buchanan (1810-1883), a wealthy, Scottish born merchant, civic leader and leading political figure in Canada West. Buchanan immigrated to Montreal in 1830 as a partner in the Glasgow based, dry goods firm of William Guild Jr. and Co. By 1832 he had become the head of the firm's Toronto operations, developing it into the largest wholesaler in the city. Buchanan gained his greatest corporate prominence however, as a partner in Buchanan, Harris and Co., a Hamilton based wholesale company formed in 1840 that became one of the largest and most profitable of its type in Upper and Lower Canada.