Is the "greeting of the mosque" (tahiyat al-masjid) obligatory for one who lives in it every time he enters his room?

If the room connected to the mosque has been prepared to be part of it, then it takes on the rulings of the mosque, such as the prayer of greeting the mosque (Tahiyyat al-Masjid) and the prohibition of a menstruating woman from staying in it. However, if it is designated for other purposes, such as teaching or as the Imam's residence, it does not take on the ruling of the mosque. If the intention is unknown, the general principle is that whatever is within the mosque's perimeter wall and has a door opening onto it is considered part of the mosque.