Set up house
Definition 1 of 1
Pro Tip 1/3Life Stage
Often used when people start living independently, marry, or want to create a family atmosphere. 
My sister plans to set up house once she finishes college.
Pro Tip 2/3Commitment Implication
Implies a significant step and long-term commitment to a living space, not just temporary accommodation. 
They didn't just rent a place, they decided to set up house and invest in furniture.
Pro Tip 3/3Cohabitation
May suggest that two or more people are moving in together to share a home. 
After a year of dating, the couple is excited to set up house together.