Editor’s Note: A version of this story was published in the Winter 2025 issue of Extant, a publication of the Preservation Alliance for Greater Philadelphia.

Restoring the chimneys posed the biggest preservation challenge in terms of materials. The repair involved infusing the inside of the bricks with a strengthening solution, then infusing their surface with a breathable, water-repellent solution. | Photo: Peter Woodall

Before the Fairmount Park Conservancy could move into its new headquarters in the 19th-century Ohio House, the organization sent its conservation team to implement a series of desperately needed repairs at the Gothic Revival-style building. Extant spoke with the Conservancy and Director of Conservation Tom McPoyle about how the team of preservationists balanced modern needs and safety standards with architectural preservation.

Extant Magazine (EM): What was the building’s original use?

Tom McPoyle (TM): Ohio House is one of only four park buildings that remain from the Centennial International Exhibition, also known as the World’s Fair of 1876. At the time, the U.S. had 37 states, and 26 of them constructed exhibition buildings. Ohio House showcased the Buckeye State’s natural resources, made from sandstone mined from 21 Ohio quarries. The building was open intermittently after the fair and had been shuttered for decades before briefly reopening in 1976 for the bicentennial celebration. It became the Centennial Cafe in 2007, then the Hungry Bear Cafe before closing in 2016.

EM: What was most important to preserve?

TM: The objective of the Conservancy’s building conservation services team is always to preserve the historic building materials and respect the integrity of the building. The function of inside rooms needed to change. But instead of moving walls, we moved doors to create better access points. The Conservancy took a preservation-minded approach and found the function of each room by looking at the spaces “as they are” and envisioned the best ways to use each space, rather than assuming there would be a need for big alterations.

The Conservancy found the function of each room by looking at the spaces “as they are” and envisioned the best ways to use each space, rather than assuming there would be a need for big alterations. | Photo: Peter Woodall

EM: What was the original vision for the restoration?

TM: The original vision was to create useful, functional office spaces without doing major surgery. Some new dividing walls needed to be added, but this was done without cutting through the original flooring or plaster walls or destroying the baseboard and window trim. We scribed the walls around these features so that in the distant future, if the building has a new use, the new dividing walls could be removed and the original floor plan restored. We measured original features for scale and size, but made the trim and doors minimal and more modern so they are easily distinguished as alterations but blend in visually.

EM: What was the biggest preservation challenge?

TM: The chimney restoration was the biggest preservation challenge. A previous contractor had either aggressively power-washed or maybe sandblasted the brickwork, removing the protective skin created during the brick’s firing process. Without their protective skin, these bricks pull in and hold large amounts of moisture. The repair involved infusing the brickwork with a strengthening solution, patching some cratered areas and infusing the surface with a breathable water-repellent solution.

EM: Did you look to any role model for inspiration or example?

TM: An indispensable resource for the exterior restoration at Ohio House was original photos and documents created for the Centennial Exhibition in 1876. From the photos, we could confirm what was intact and what was missing on the three main elevations of the building. We also confirmed the types of materials, along with the names of suppliers, from 1876 documents. The original glass in the windows was manufactured with a high-silica limestone quarried in Ravenna, Ohio by the Diamond Glass Company.