Those who pay attention to such things can often tell the age of a house by certain features of the architecture. You might be able to do that with hospitals, too, if you know something about the history of hospital architecture. Smithsonian offers us a clue with an excerpt from Jeanne S. Kisacky's book Rise of the Modern Hospital: An Architectural History of Health and Healing. The feature in question here is windows. Did you have a window in your room the last time you were a hospital patient? The answer may indicate how old the facility is.
In the March 1942 issue of the journal Modern Hospital, Charles F. Neergaard, a prominent New York City hospital design consultant, published a layout for a hospital inpatient department that was so innovative he copyrighted it. The plan held two nursing units—groups of patient rooms overseen by a single nursing staff—in a single building wing. For each unit, a corridor provided access to a row of small patient rooms along a long exterior wall and to a shared service area between the two corridors.
The feature that made his plan so innovative—and therefore risky? It included rooms that had no windows.
A windowless room hardly seems daringly innovative nowadays, but in the 1940s it was a shocking proposal for a patient wing. It violated a long-lived understanding of what, exactly, the role of the hospital building should be in terms of promoting health.
To explain how a windowless hospital room became possible, and why it was resisted so strongly by medical professionals in the 1940s, you need to know a little about the history of hospitals and their intended purpose, which you can read about at Smithsonian.