The Monadnock Building

The last great masonry skyscraper

The Monadnock Building's north half, completed in 1891 by the firm Burnham & Root, represents something close to the absolute limit of what load-bearing masonry construction could achieve before steel framing made the whole approach obsolete. To support sixteen stories entirely on brick walls carrying their own weight down to the foundation, the building's base walls run roughly six feet thick — a genuinely enormous amount of material dedicated purely to holding the structure up, none of it available as usable interior space. It's widely cited by architectural historians as the tallest load-bearing masonry structure ever built, a superlative that exists precisely because almost nobody tried to push masonry construction this far again once steel framing proved a better answer.

The building's severe, almost unornamented exterior — a smooth, gently battered brick wall rising without much of the terra-cotta or stone detailing common on its contemporaries — is itself partly a function of that structural extremity: every additional ounce of ornamental stone would have added load the walls below had to carry. The result is a building whose plainness is actually a direct expression of its engineering constraints, not a stylistic choice made independently of them.

The Rookery Building

A near-contemporary Burnham & Root building a few blocks away, from the same transitional moment.

Birthplace of the Skyscraper

The 1885 breakthrough that made the Monadnock's south half — and everything after it — possible.

One building, two structural eras

What makes the Monadnock Building genuinely unique isn't just its north half's extremity — it's that just two years later, in 1893, the building was extended southward using steel-frame construction, the same technology that had made the 1885 Home Insurance Building possible. The two halves are connected into a single continuous structure, meaning a walk down the block moves you physically from the heaviest masonry high-rise ever attempted directly into the lighter, steel-supported construction that immediately superseded it — a transition you can see and, in a real sense, feel, since the base of the north half is noticeably thicker than anything in the south half.

The building remains a working office tower today, its long dark-brick lobby open to the public during business hours, and it sits within an easy walk of The Rookery and the birthplace-of-the-skyscraper plaque, making it one of the clearest, most walkable single lessons in the whole story this category tells. Few buildings anywhere let you stand inside the exact hinge point of a major construction-technology shift; the Monadnock does, in one connected structure.

• North half (1891): load-bearing masonry, roughly 6-foot-thick base walls — the tallest such structure ever built.
• South half (1893): steel-frame construction, added just two years later, in the same connected building.
• Lobby is publicly accessible during business hours; it's a working office building, not a museum.

The Loop Architecture Walking Tour

The Monadnock Building is one of the anchor stops on this self-guided route.

The Loop

The neighborhood holding the densest cluster of this early skyscraper history.