Due to economic situation, lots of people find themselves doubling up. Adult kids move in with parents. Parents who've lost their pensions in the market move in with kids. Siblings move in together, complete with spouses and assorted children. Maybe it's a group of friends pooling funds to share a house.
Most Americans haven't had to deal with the dynamics of extended family living. It's going to be a time of adjustment for everyone involved. There's some bad things to deal with, but some benefits too.
Everyone will have to make some adjustments. If you are the owner of the house and feel that you won't have to adjust, it'll just end in tears. Everyone has to learn to give and take. There are many ways of handling it. The most important thing is to keep the lines of communication open. The easiest way to do that is to share at least one meal a day together. You have to eat, might as well eat all together. Sharing good food puts everyone in a more congenial mood, and that helps communication along.
The size of my household changes from year to year. Right now my wife and I share the place with one of my daughters and her daughter. She's reestablishing herself after a nasty divorce. Some observations in no particular order: Mommy is the boss. My daughter is the parental authority for my granddaughter. My wife and I try hard to not undermine her authority. She's a great mom so it's not really a problem. Grandparents make good babysitters. It's good to be able to share food, energy, and vehicles.
We've had up to 6 adults under our roof -my wife and I, two of our daughters plus their spouses. It wasn't always easy. Everyone had different expectations. One couple was trying to save money to buy a house of their own. The problem was they'd gotten used to doing things a certain way in their apartment. It's tough to give up part of your independence. Then there were issues of the level of order and house keeping standards. I must admit that my standards are more lax than that of my kids. It caused a bit of stress.
Food is an issue. What's bought for communal use? What's for individual use? It's a source of friction when someone buys something for their lunch only to have it disappear during a midnight food raid. Maybe establishing separate sections of the refrigerator or pantry is a good idea. There may be times when someone who could be contributing to the communal food isn't doing their part. It doesn't even have to be a conscious thing. They may find themselves too busy to do grocery shopping. I've found that after a few days of eating our of the deep storage is a good wake up call. I didn't complain about being the only one bringing in fresh food. Instead I cooked a lot of beans and rice, rice and beans, bean soup, pea soup, whole wheat bread from stored wheat berries, and them some more beans and rice. They caught on.
Last summer we had 4 generations living here. Dad came up from Florida for a month long visit. It went fairly smoothly. One thing my wife and I did was to set up a tent in the yard. That's where we slept. It was great. We could look up at the stars at night and listen to the loons. If we wanted to do the wild monkey dance, we had privacy. It took a bit of convincing for my dad to understand that's how we wanted to live. My wife and I love tents. The grandkids had fun playing the tent during the day. Good fun all around.
From my studies of anthropology, I've figured out how tribal people live together. Sure, sometimes they are all crammed together in a small space. However, they have ways of establishing some privacy and personal space. Men may go out on a long hunt -even when they don't really need the food. I'm sure the women are happy to see them go. Some tribes would even split apart for a few weeks or months. By the time they'd get back together again, everyone was happy to see each other once more. Each group would have something new to talk about.
If you do share a house, try and establish some personal space. If each couple can have their own room that helps. No one goes into the private room without permission. They can decorate it anyway they want. I always figured that if I didn't like what the did to the room I could change it after they moved out. Paint is cheaper than conflict. Should the situation arise where private rooms are not possible, the old seaman chest is the way to go. Have something like footlockers where people can keep private things.
Establish a place where someone or a couple can go for privacy. It's important.
Duties can be shared. Cooking, cleaning, gardening, firewood gathering, childcare, vehicle maintenance, house repairs and many other things go better with more people. As long as everyone is contributing, it goes fairly well. Keep lines of communication open. Remember that sometimes a bit of physical distance is a good idea.
It used to be the way everyone lived. We can learn how to do it again.