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.