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Parkwood Estate National Historic Site: Greenhouse Conservation

Greenhouse at the Parkwood Estate National Historic Site.
Greenhouse at Parkwood Estate National historic site
Parkwood Estate National Historic Site Greenhouse
Parkwood Estate National Historic Site - Greenhouse Conservation
Parkwood Estate National Historic Site - Greenhouse

Parkwood Estate National Historic Site: Greenhouse Conservation

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Oshawa’s Parkwood Estate was erected in 1915 as the home of automotive industrialist Colonel Sam McLaughlin, who had a keen interest in horticulture. Designed by the leading establishment architecture firm Darling & Pearson, the estate included five greenhouses, with additional greenhouses added over time. The estate is now a National Historic Site.

After the property was transferred to a local hospital in 1972, all but six of the greenhouses were demolished. Alterations completed in 1970s or ’80s replaced the greenhouse glazing with Lexan sheets and removed the curved eaves in all but one greenhouse. The replacement materials, not well suited to the high humidity levels and sun exposure of the greenhouse environment, had deteriorated over time and were beginning to fail. The Greenhouse Conservation project was the final phase in a long-term study of the greenhouse complex that informed the conservation strategy. This included the preservation and selective reintroduction in kind of original building fabric and the restoration of the original glass cladding and curved eave design.

ERA and Heritage Restoration Inc. worked closely together to document and review the existing conditions in previously inaccessible areas prior to dismantling and salvage work. Due to the condition of the greenhouses, it was determined that the best strategy was to dismantle, repair, and reconstruct them. This allowed for the repair of obscured and inaccessible elements and the provision of protective coatings on the metal components. A variety of custom wood, glass, and metal pieces were manufactured to match the original components. These character defining elements were ordered and produced after the greenhouses were dismantled to ensure as close a match as possible.

The Greenhouse Conservation Project celebrates the use of these important structures while providing a National Historic Site with increased capacity for community programming.

Oshawa, Ontario
Parkwood Estate


  • CAHP | ACECP Awards: Conservation: Small & Lovely, 2019
  • Lieutenant Governor’s Ontario Heritage Award: Excellence in Conservation, 2019

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