# to the day of his death

"until he died" 

# lived in a separate house

He lived away from other houses and other people.

# he was cut off from the house of Yahweh

"he was excluded from the house of Yahweh" 

# Jotham, his son, was over the king's house

"Jotham, his son, was responsible for the king's house" 

# the king's house

This refers to the king's palace, which the king was no longer living in.