In Pakistan and other parts of Southeast Asia, joined families are still pretty common. Many families have sometimes four or more generations living in the same house. Usually it is the sons that stay in the family house and bring their wives to live with the family, while the daughters get married and go to live with their husband and his extended family.
As the sons get married and the family grows some families may branch out and others will put an addition on the house(that's what our family did- added the second and third floors to make enough space). Generally each son(and his wife) will have their own bedroom(sometimes with attached bathroom), but then all the other rooms will be common rooms. Like in our house there is one bedroom for Tariq's father, one for his sisters, and then one for us, and one for his brother and his wife.
There are some benefits and some drawbacks to living in a joined family system.
One benefit is that it is easier to support the parents as they get older. Instead of all the responsibility falling on one child, all the sons work and contribute to the household. Another benefit is that with so many people around it is not as difficult to cope with when one person is ill. There are so many people that it is no problem to keep up the cooking, cleaning and child care as well as tending to the sick one.
For example if I get sick I don't have to worry that dinner won't get cooked, or that I'll have to chase after Saad while I'm ill. I have the comfort of knowing that Tariq's brother's wife will take care of dinner or his sisters can help take care of Saad. And when one of the others is ill I do the same.
Some of the drawbacks is that when there are so many people living together little arguments can break out over small things. Like whose turn is it to clean the common bathrooms, or to sweep/vacuum the common areas. It can also be difficult to find privacy if you just want to spend a bit of time alone.
My main problem is that brother's in law are not maahram(close relative who can see a woman without hijab). So when Tariq's brother is here in Karachi I have to wear my hijab at all times, unless I'm in our bedroom. Right now it isn't really a problem because my brother in law spends most of the year in Abu Dhabi.
So, while it has been an interesting experience living in a joined family, I am kind of looking forward to living on our own again eventually.