What began with a professor’s frustration in 1883 sparked a revolution in building automation. Discover how Warren Johnson’s invention of the electric thermostat laid the foundation for Johnson Controls—and the smart infrastructure shaping our world today. 

How one inventor sparked the smart building era

In 1885, Johnson Controls was founded on a single idea: buildings should be smarter. That idea came from Professor Warren Johnson, whose classroom in Wisconsin was always too hot or too cold. He was also constantly being interrupted by a janitor who came by hourly to check the temperature and adjust the basement furnace dampers. 

Rather than accept the inconvenience, Johnson invented a solution: the first electric room thermostat. Patented in 1883 as the “electric tele-thermoscope”, it brought order, automation and comfort to a previously chaotic system. By 1885, Johnson had launched the company that would become Johnson Controls. His goal wasn’t just to solve one classroom’s heating issues; it was to transform how buildings function. 

His invention gave birth to the field of automated building controls—and a company that would go on to shape global infrastructure. It marked the beginning of intelligent building management. From schools to factories, the idea that a system could monitor and regulate itself transformed how people thought about indoor environments. It laid the groundwork for a legacy that would redefine how we heat, cool, power and protect the spaces where we work, learn, heal and innovate.

A legacy still innovating

Today, Johnson Controls leads the world in intelligent building technologies, providing advanced solutions from HVAC systems and security to fire protection and environmental sustainability. And at the heart of it all? The very principle Johnson pioneered: precise control for greater comfort, safety and performance.  The same company that started with the electric thermostat now equips skyscrapers with cloud-connected systems and advanced AI that optimizes energy use in real time. Hospitals, universities, stadiums and data centers—Johnson Controls technologies quietly orchestrate the critical functions of the world’s most complex buildings. 

We’ve come a long way since that Wisconsin classroom. But Warren Johnson’s core idea remains unchanged: innovation should serve people. It should make buildings smarter, lives easier and our shared spaces more sustainable. Because one cold classroom in 1883 didn’t just inspire a better thermostat, it inspired a company—one still engineering the global infrastructure of tomorrow, every single day.