Child custody norms have changed considerably over the past decades. Moms used to traditionally have primary custody of the kids, with dads spending weekends and maybe a weeknight with them. Now parents are more likely to split their time evenly with the kids. However, this means a lot of moving back and forth between two homes for those children.
Some parents whose primary goal is to keep their kids' lives as stable as possible are trying another type of custody that's commonly referred to as "nesting" or "bird's nest" custody.
The way this custody arrangement works is that the kids stay in the family home (or in a new home that the parents purchase) while the parents alternate staying with them. One parent moves in for a week or two while the other parent goes to live somewhere else, and then they switch. This gives the kids equal time with their parents, but they don't have the disruption of schlepping books, clothes and other belongings back and forth between their parents' homes or needing two sets of everything -- one at each house.
Of course, not everyone can afford to keep two homes, so unless they can find an understanding family member or friend to stay with, bird's nesting may not be feasible. It also generally requires a home large enough that each parent has his or her own room and space that's separate from that used by their ex. It also requires some communication between spouses regarding groceries, utilities and other household responsibilities, so it may not work if things between exes are strained.
A variation on this custody arrangement involves the entire family continuing to live together in the same home. Parents go about their business separately, but are both available for their kids. Again, this isn't feasible for a lot of people. Your house may not be big enough to avoid running into each other constantly. It may be a temporary solution, however, at least during the early days of your break-up.
Custody arrangements are as unique as the families involved, and no custody arrangement has to be "permanent." If a nesting arrangement is something that you and your spouse would like to try, talk with your family law attorney about codifying it in your parenting plan and custody agreement.
Source: Chicago Tribune, "Why modern custody agreements look so different: 'Anything goes, as long as the children are happy'," Danielle Braff, March 08, 2018