Is the supplication for leaving the home to be recited when departing the apartment door or the entire building's door?

It is recommended to engage in remembrance (dhikr) upon entering or exiting one's private home. The Prophet, peace and blessings be upon him, when he would leave his house, would raise his gaze to the sky and say: "O Allah, I seek refuge in You lest I stray or be led astray, or slip or be made to slip, or oppress or be oppressed, or act ignorantly or have ignorance acted upon me." And upon entering his home, he would say: "O Allah, I ask You for the best of entry and the best of exit." This supplication is specific to one's private home, and not public places, as indicated by the explicit mention of "home" in it.