The idiomatic expression "Out of the House" means to leave one's home or residence and go somewhere else. It can refer to going for a walk, running errands, traveling on business or vacation, attending an event, visiting friends or family, etc. The phrase is often used in phrases such as "I need to run some errands so I'll be out of the house all day" or "My parents are going out of town next week, so they asked me to keep an eye on their place while they're away."