The Provincial Government took possession of about 24 hectares (60 acres) of land fronting Lake Ontario in May of 1888 after trading a portion of the Mimico Farm land for the land owned by Benjamin Gouldthorpe (alt. Goldthorpe). Once acquired, the plans for the construction of the Mimico Branch Asylum were relocated from the Mimico Farm site to the new property. In reporting on the news, The Globe raved that "A better location for asylum purposes could not be had in the vicinity of Toronto" (1 June 1888, p. 3). With its quality soil and proximity to Lake Ontario, the paper compared the site favourably to the Rockwood Asylum in Kingston.
The buildings of the Mimico Branch Asylum were formed from three layers of locally sourced materials: (1) lake stone; (2) sandstone; and (3) brick. The construction plans specified the exact materials to be used, as well as their sources. The foundation of the buildings were to be made from:
"...good rubble Lake stone, procured in the neighbourhood, laid in mortar composed of three parts of clean sharp sand, and one of Napanee, Thorold, or Hamilton cement, in fifteen inch courses. If preferred by the Constractor, the stone can be quarried on the ground near the Lake shore" (Specification for sundry work required for the erection of eight cottages.... Archives of Ontario, RG 15-5501).
Although Etobicoke Creek was commonly quarried during the period for construction stone, the detailed contractor specifications clearly indicate that Lake Ontario stone was to be the primary resource, particularly the immediate shoreline to the property.
The mid-layer of construction, encircling the individual buildings at ground level, was to be Credit Valley brown stone.
Lastly, the reddish bricks which provided for the characteristic styling of the buildings were to be purchased from the brickyard of the Central Prison in Toronto although the plans did allow a caveat that bricks could be procured from elsewhere should the supply at the Prison fall short due to the demand from the construction of the new Parliament Buildings.
The contract for construction was awarded to brothers John and Edward Dickinson of North Glandford, Ontario in 1888 with construction on the cottages continuing until 1892.
The original agreement between the Province and the Dickinson brothers specified a construction completion date of December 1, 1889 but when the Mimico Branch Asylum was officially opened on January 21, 1890, only two cottages were available for occupancy. The Medical Superintendent, Dr. Daniel Clark, complained in his annual report for the year that the buildings weren't even complete when patients were first moved in.
The exact construction schedule and build order of the cottages is not known, although the annual reports indicate that the third and fourth cottages were completed and occupied by November of that first year, with construction to four additional cottages under way by this same date.