You want to choose a layout that is going to work for you and the other purpose of the room. You want to pick a “sharable” layout for your office and create a space that is conducive to sharing. They don’t need to be equal parts, but sufficient for the use of the room. You would never slap your desk in the middle of the living room and have rest of the furniture on the surrounding walls.
This is important because everyone needs to feel like they have a place in the room. You don’t want anyone feeling like they are imposing on your office space, and not be able to enjoy the room for it’s other purpose. So when you dedicate areas of the room, make sure you have some separation of furniture that makes it look like it is it’s own little room.
There has to be respect for everyone’s area. Kids are likely going to be the biggest challenge in this area. If they are young, they are exploring the world as they know it and who wants to tame that? Let them learn and enjoy life right? But not at your workspaces expense. With the little ones, you will have to create boundaries for them, just like baby proofing any other area in your home. With kids that are older, rules will have to be in play. And if you have rule breakers in your house, like I do mine, stick with it. It’s bound to work at some point lol
Asking the family to join in making the space livable for all is essential to enjoying the room in harmony. Have a family meeting about the space, let them know how important it is for you to be able to work there, as well as them to have fun. It can all go down in one room. It is possible. It may take some tweaking based on use of the room and your family’s routines, but that’s the process.