When most visitors walk up the long drive to Glensheen, they are immediately drawn to particular details, such a its rich red brick walls, beautiful landscape, carved stone accents, and a dramatic view of Lake Superior. What is often overlooked, is the story beneath the surface: a story of family, engineering, intentional environmental adaptation, and architectural creativity that made Glensheen not just a mansion, but an early 20th century infrastructural experiment. 

The focus of this post is on Glensheen's structural design, and questions like: How do buildings communicate the values and vision of their architects and patrons not just through decor, but through the engineering decisions invisible to the casual visitor? Glensheen's exterior promises Jacobean-revival, but the structure within reveals something more modern, more practical, more efficient, and more reflective of the Congdon family's ambitions for permanence on the lakeshore. 

Construction of Glensheen's main house began in 1905 and continued steadily until 1909, ultimetly producing a 39-room mansion designed in a Jacobean style closely related to Tudor-revival architecture. The stylistic choice makes the mansion appear older, and is an ode to the Congdon's English ancestry. 

But within this historical exterior is another whole story, a story of steel. 

Hidden beneath the brick is a steel-beam frame which is a structural feature more commonly associated with urban commercial construction than with residential lakeside mansions. This skeleton supports both the roof and the overall load of the building, freeing the designers to focus on the structural Jacobean facades without sacrificing stability. It also positioned Glensheen at the intersection of tradition and modernity: a house that looked centuries old but had all the efficiency of a new age.

One of the most compelling aspects of Glensheen's construction is the Congdon's attention to environmental infrastructure with intentionality. Duluth's lakeshore is beautiful, but is also harsh as anyone who has lived here would know: freezing winds, heavy snow loads, unstable shoreline soils, constant moisture and crashing waves all have to be taken into account. 

In response many parts of construction were engineered with these factors in mind. 

Along the mansion's south wall, the Congdons installed a large, reinforced concrete foundation. This was not common practice for residential architecture of the period. Concrete was still in a transitional phase between industrial and residential use, and offered superior stability on the shifting ground on the edge of Superior. Its inclusions suggest the Congdons, their construction supervisor J. C. Bush, and their architect Clarence H. Johnson Sr., understood the risks of building in such a location and took them seriously. 

Unlike many Gilded Age estates built more for display than practicality, Glensheen was notably shaped by its environment. The area surrounding the house was carefully excavated and sculpted to withstand the surrounding landscape. The steel frame not only allowed more elaborate external detailing, it also increased the building's resistance to the wind coming of the lake. The concrete foundation added stability in an area prone to moist soil. 

Gleensheen's structural design communicates not just aesthetic taste, but adaptation and foresight. It is a building that acknowledges its surroundings rather than imposing on them.

While Glensheen's exterior nods to Jacobean-revival architecture, its interior organization borrow elements from Baroque design, particularly in its approach to spatial hierarchy. 

The ground floor; the home's public stage contains the most elaborate, grand, and expansive rooms within the greater estate, including the library, dinning spaces, and drawing room. These rooms are larger, more elaborately ornate and decorated and meant to impress guests. Their size was made possible, in part, by the steel beam structure, which allowed wider room spans without the heavy reliance of bulky load-bearing interior walls. 

The private upper floors, by contrast are more humble, modest and practical. Structurally this spatial distribution reflects more modern social and structural norms of the Baroque and Gilded eras, rather than the Jacobean era.