What is the ruling on leaving the Haram area to reside or for other reasons before completing the pillars of Hajj?

There is no harm for a pilgrim (muhrim) performing Hajj or Umrah to leave the حرم (sacred precinct) and go to the حل (non-sacred area). This does not affect his state of ihram or his Hajj. Ibn Uthaymeen was asked about the permissibility of leaving Makkah for Jeddah or Ta'if for someone who was observing some of the rulings of Hajj or Umrah, and he answered that it is permissible, affirming that it does not invalidate the Hajj.