I would assume older buildings to have larger floor plates? Many of New York's newer skyscrapers, esp. the "one luxury apartment per floor" kind, are really skinny.
Older office buildings tend to be geared towards small offices for smaller businesses, like small law practices. Modern cubicle farms are much larger, open offices even more so.
Also, older regulations on building forms pre-war required more setbacks at taller heights, creating the “wedding-cake” style tower common during that time. The modern glass box is generally wider.
