I work in a building which dates back to 1908, and which has been added onto
several times. We have not had any roaches for the last 10 years.
I attribute this to the ongoing fumigation program, and general level of
cleanliness.
Occasionally I see a bug on the floor, but always on its back.
Just because an occasional roach get in, doesn't mean you will have an
infestation.
I have to admit I worry sometimes about the amount of toxins in my work
environment!