Designed by E.J. Lennox and built by Sir Henry Pellat between 1905 and 1915, Casa Loma is a civic monument and an international landmark, reflecting the potential that existed in Toronto during the Edwardian period.
By the 1990s, the exterior building envelope was in an advanced state of deterioration and the building was at a point of selective closure because of increased frequency of falling debris.
THA developed a phased Conservation Master Plan, after which the City embarked on a restoration program of the designated structures to address dramatic public safety issues. With the completion of each successive restoration project, selectively closed spaces were returned to public use.
Complexity of materials, building height, the scope of deterioration and the need for the site to remain open throughout construction presented unique challenges to completing the project. Roman stone, the precursor to precast concrete, had to be used in combination with natural sandstone. When THA began restoration, it was evident that the roman stone was extremely deteriorated. The architects were assisted by material scientists, engineers, the National Research Council, manufacturers and contractors in conducting archival research, followed by a two-year testing program to refine material formulae and manufacturing techniques for roman stone that could be used as a patching and casting material.
The new casts in roman stone included allegorical figures, floral and vegetative motifs, heraldic symbols, volutes, columns, cornices, architraves, chimney caps and copings. The roman stone developed by THA is now a standard for the restoration industry in Canada.
The project also involved the conservation of hundreds of leaded windows, the stained glass ceiling in the conservatory, copper, lead and tile roofs, and sandstone and brick masonry. Larger scale assemblies included structures 20 metres in length, verandahs, chimneys, foundations and three towers. THA enforced quality control for all conservation work over a fifteen-year period and received several awards for this project.
