Allan Gardens Palm House Restoration

Archival images courtesy of the City of Toronto’s Parks, Forestry and Recreation department.

First opened in 1910, the Palm House was designed by City of Toronto architect Robert McCallum and is the third horticultural pavilion on site. Edwardian in style, the building’s architectural features point to an era of rapid technological advancement in glazing systems. Said to be the last remaining structure of its kind in the country, the Palm House’s design is a nod to a period when Toronto was still heavily inspired by the trends in English horticulture and botanical garden design. The structure is anchored by a central 16-sided dome made up of curved trusses supporting the glazing, with two smaller domes located at square corner pavilions. Topped by a small cupola, the large dome is easily visible from across the park.

A principal component of the project is the reinstatement of a central entrance at the eastern portico, a key element of the original design. Once located behind a free-standing colonnade, this main entrance helped complete the historical axis that terminates in front of the Palm House. The new projecting entry bay with double doors offers barrier-free entry to the conservatory, accommodates access for heavy machinery for maintenance, and creates a more prominent entrance. It will ultimately reinforce the connection between the building and its front plaza. The doorway takes cues from the original design, echoing historical features like the transoms located above the sandstone-finished base of the building. This was done in collaboration with heritage architects AREA, who led the refurbishment of building elements like finials, the entablature, and the sandstone façade. 

To create a better performing enclosure, the overhead glazing of all three domes was replaced with fritted glass panels. The restoration of the framing ensures the historic appearance is kept. Coupled with improvements to mechanical and electrical systems, the retrofits result in better indoor air quality, energy efficient operations and more stable indoor temperatures. A new, wider catwalk is also installed, once again helping improve access to the upper reaches of the dome for maintenance.

The project is a collaborative undertaking between the City’s PFR department and Zeidler Architecture along with AREA heritage architects, with RJC and HIDI supporting engineering efforts. Part of a broader vision led by the city and the Friends of Allan Gardens, the restoration and functional upgrade of the Palm House will make Allan Gardens more accessible and enjoyable, while making sure that the distinct architectural language of the site is preserved for generations to come. The conservatory’s greenhouses remained open during renovation, with the Palm House’s plant collection temporarily moved offsite.