Multi-generational homes are common in many places and are becoming more common in the US for so many reasons. But, not everyone has the space for more than one generation in one house or wants to have their family in the exact same house but still want to have their family near them. There are various ways to still make this happen. One way to do this is to buy a multi-family house like a duplex or even something like an apartment building. There are some really good reasons to do it this way.
One reason that you might want to get a multi-family home to use for a multi-generational home is that every family is going to have their own space. You might love having your son or daughter and their family living with you, but there may be times when you want to be able to have your own space around you so you don't really have to deal with anyone. If you have a multi-family structure, you can retreat to your own space and take a break and catch your breath before you get back together with your larger family again.
Another reason that going this route is a good idea is that even though you are living in such close proximity and are able to help each other out as necessary, your family member is going to have some independence. If you have an adult child who has some kind of disability that will make it hard for them to live completely independently, sharing a duplex can mean that your child has some independence and can do some things on their own but that you are also going to be there as backup and support as necessary. It would work the same way for an elderly parent or family member. You are going to be right there to help them if they need it, but they will also still feel like they are living in their own space and as independently as possible, which is really important to most people.
Multi-generational homes are becoming more popular every year. There are a variety of ways to do it, and no one way is right or wrong. The only right way to do it is the way that works best for your family, and that may be to buy a multi-family home for your family to live in. Contact a real estate agent and ask them to show you some multi-family homes for sale.