The Great Chicago Fire Changed Building Code Forever


On October 8th, 1871, The Great Chicago Fire began in the barn of Patrick and Catherine O’Leary, destroying over 17,000 buildings and costing millions in property damage. Legend has it that the O’Leary’s careless cow who owned the foot that struck the lantern, taking four square miles of Chicago down with it. However, according to the U.S. Fire Administration, the second leading cause of residential fires is due to cooking accidents; so perhaps a deep fry turned devastating in the O’Leary’s home all those years ago. Either way, the O’Learys and their poor cow have been cleared.

No matter who was ultimately responsible, the event is linked to change in Chicago’s architectural trajectory.

Fire Prevention Week started in Chicago, and an extremely stringent Fire Code has changed the way we live, work and play in residential and commercial spaces. And then there was the matter of Chicago’s building material of choice in the 1870’s. It was practically made of Lincoln Logs (incidentally invented by famed Illinois architect Frank Lloyd Wright’s son John Lloyd Wright)—or at least many buildings had wooden elements, if not being entirely made of wood.

After the fire, laws were passed to prevent the same thing from happening again. Materials like brick, limestone, marble and Terracotta tile became the preferred building materials and wood was banned as a material in the downtown area. This contributed to a lot of local materials finding their way into our signature industrial style, like these made-in-Chicago Brisch bricks.

The Palmer House was among the first reconstructed buildings to declare itself fireproof, and is a great example of Terracotta tile in Chicago architecture. The Great Chicago Fire is also commonly considered a catalyst for the skyscrapers that create our signature skyline. Because fire proof materials were categorically heavier, steel “skeletons” with deep foundations were explored as a way to maximize efficiency in a given lot by building it high without all the heft of masonry. Grant Park might not have existed if we didn’t have The Great Chicago Fire: it was built on all the rubble that people dumped right into Lake Michigan.

Fire Code started back as early as The Romans (and probably earlier), who experienced a massive city-decimating blaze around 64 A.D. The guys in charge made a couple tweaks to city-building that you might recognize:

  • Wider streets
  • Common walls between buildings needed to be fireproof
  • No super tall houses

(Source: The Whole Report is Fascinating)

Flash forward to 1736. Firefighters were a volunteer task force consisting of thirty guys with some extra time on their hands. Homes were required to have a bucket for volunteer firefighters to happen upon if there were to be a fire. By the Great Chicago Fire there were actual Fire Departments, but they were understaffed, which contributed to the length and breadth of the fire.

In the early 1900s, a horrific fire at the supposedly fireproof Iroquois Theatre killed over 600 people, which led to further changes in Chicago. 

  • Enclosed fireproof stairwells and mandated unlocked fire exit doors that opened outward came out of this. Unfortunately exit doors did not always open outward, only inward, which in hindsight was obviously no help to patrons trapped in an emergency.
  • Clearly marked exit signage and maximum capacity limits were also a result of this disaster.
  • Exits were blocked, obstructed or otherwise impeded during the fire. If these exits had been clear, the fire may not have resulted in so many casualties.
  • This is why it is illegal to obstruct, block or even sit in front of an exit or in rows today; it is a fire hazard in the event of an emergency.

Here are some current requirements pulled from the Chicago Building Code and Fire Code:

  • Fire walls divide the building (or two buildings, if they share walls) with protective fireproof walls that are designed to halt the spread of a fire. Fire wall resistance is measured in hours, e.g., how long can this non-combustible material withstand a fire?
  • All boilers must be contained in a non-combustile material that can burn for at least two hours.
  • Does your building need some extra insulation of the plastic foam variety? It must be coated in a synthetic stucco coating or another approved material. And if it does catch on fire? It better not be more toxic than burning untreated wood. Obviously inhaling smoke from any source, even if its just a campfire made of forest sticks is not healthy, but it’s probably less toxic than most burning plastics. This is why the city sets requirements for building materials requiring them, in the event of a fire, to not release any worse toxins than your average tree.
  • Got rugs? Yeah, those need to be vetted against fire code, too along with all other floor coverings and materials.

These things may seem standard now, but each and every portion of our building code has been added with intent, either to mitigate injury and death in the event of an emergency, to promote accessibility or to enhance weatherproofness. Our building code may not be perfect, but it does its job well. If you’d really like to dig into our fire code it’s all on the City’s website.

Pre-fire, Chicago was one of the fastest growing cities in America. Post-fire, people picked up the slack and kept it that way. Visionaries like Daniel Burnham, Louis Sullivan, Dankmar Adler and Potter Palmer revolutionized city planning and shaped the Chicago School of architecture in a string of innovative years. This style was characterized by a sleek, unadorned look that is apparent in our downtown.

Don’t forget though, that this architectural marvel of corruption and comedy is built on a swamp that, just over 100 years ago, was also on fire. No wonder they call us the Second City.

To improve drainage to the our squishy city, Chicago embarked on campaign to literally raise the entire city up a notch. They did it with men and cranks and pulleys and wheels, and most oddly of all, as houses and buildings were being raised, people were going in and out of them as though nothing was happening. Of course, not everyone had the cash to pay scores of ripped men to lift their homes up—so they simply moved upstairs to the second floor of their homes and also acted like nothing odd was happening. When the sidewalks were brought up, it would appear that their homes were slightly “sunken.”

If you walk around in Chicago’s Pilsen neighborhood, you can still see some of these homes, which look as though the sidewalk was built halfway up their sides. These homes are also largely brick, the material that has become synonymous with both Chicago industrial and the warmth of Chicago’s single family homes and it’s use of local materials. And of course it’s fireproof-ness and general stability. The housing stock in Pilsen is very unique, showcasing both the Bohemian and Mexican communities that have shaped Pilsen, and fought to preserve it’s look, feel and culture. 

Murals and street art are abundant in Pilsen, adding character to neighborhood houses and buildings.

Pilsen’s Thalia Hall was built by Saloon Owner John Dusek in the 1892. And now you know how the delicious Dusek’s got it’s name!

Want to learn more about the brick that built our city? We have a more in-depth exploration of brick in Chicago here and here.