For rendering?
Mostly kit bashing with whatever fit your boat, a little a bit of this and a little bit of that.
1. Find a house environment asset you want to use
2. Rearrange walls/rooms/surfaces to your need
3. Fit with props assets (curtains, bed, chairs...) and lights
4. group rooms (bedroom, bathroom, kitchen, roof...) to only load what you need
Or you can build from scratch but it takes more time and some planning.