Lots of group dynamics that work - growing up with 8 brothers and sisters I'll add a couple:

Eat dinner together. Its when we saw each other, griped about each other, and got bragged on or ragged on for doing something good or bad during the day. Good communication is a key to a group living situation. When I think about growing up its often about sitting around a table at dinner.

Just because [Mom] makes a meal doesn't mean she has to clean up after it - it doesn't matter whose turn it is, someone should be doing KP after every meal. We got better at this one when we got older.

Schedules are flexible and mostly belong to you - doing laundry, baseball, soccer games etc. Someone may take charge and start laundry or drive you to the ballfield, but mostly its up to you. If you want to sit on your butt until 15 minutes before a game fine, but don't expect anyone to run around and get you there on time.

We had cousins, a couple in particular who moved out to the PNW and camped at our house for as long as a couple months. I have an aunt who says that fish and house guests begin to smell after a few days, maybe so. I can't recall my mom or dad ever minding the long term guests, and our cousins are still friendly to us. When they came in though, they functioned as part of the family unit, and had to follow the same rules as everyone else.

If I had to house 16 people today, I would apply some principles learned working at the Red Cross, namely client case work: returning everyone to where they were geographically, economically, and status-wise, as soon as practical. 16 isn't long term sustainable in many modern American households, no matter how much floor space - food and living expenses are greater. You should make a plan with every transient visitor to your home, where they want to go, when they'll get there, and what they'll need or need to do to achieve it. Track the plan, and make sure that people follow through on it.

TP is key :-). I remember Mom buying TP by the pallet, literally - we kept it in a basement storeroom, and took rolls upstairs every day. A remodel added a third bathroom, much appreciated by those of us living downstairs.