"I am going out of the house."
Translation:Mi iras el la domo.
Real quick, "dormo" is "sleep", and "domo" is "house". Now using your example sentences with the one edit....
Ekster: I'm going OUTSIDE the house. (You are inside and your announcing that you're going outside).
El: I'm going FROM the house. (You're at the house and you're letting someone know from perhaps a phone that you're leaving the house in general)
Hope that helps!