What innovation in technology contributed to the demand for professional property management in the 1800s?

The innovation that significantly contributed to the demand for professional property management in the 1800s was the elevator. The invention and widespread use of elevators allowed buildings to rise higher, leading to the development of multi-story residential and commercial buildings. This change transformed urban environments and created more complex property management challenges.

As cities grew and buildings became taller, managing these properties required specialized knowledge and skills. Property management emerged as a profession to handle the new responsibilities associated with these larger structures, such as tenant relations, maintenance, and lease management. The need for efficient management practices grew in tandem with the increase in building size and occupancy.

In contrast, while the telephone aided communication, it didn't have the same direct impact on the nature of property management as elevators did. Air conditioning became popular later, and the internet, introduced much later in the 20th century, had a transformative effect on the industry but postdates the foundational changes of the previous century. Thus, the elevator stands out as the technology that prompted the need for professional expertise in managing properties effectively during that era.