This refers to entrance into a building, NOT entrance into an apartment or house.
E.g. there are some security buildings where they don’t let just anyone in, you have to be buzzed in by the person you are visiting or the manager — they do have to let a census worker into the buildings so they can knock on doors.
But see my post 24, for statement on the official census website, stating that census worker will never ask to enter your home.
“This refers to entrance into a building, NOT entrance into an apartment or house.”
Obviously houses have no resemblance whatsoever to “buildings” whatever those are.