This is one of the most important things to understand when looking to buy a caravan. It has a direct impact on how the caravan will be used and will govern the layout choise above all other factors.
This can be a simple question, ie, two people, three people, four people ect, which if the answer is that simple, you can go ahead and find the answers to the next set of questions, or if it is more complicated, read on.
If you know you will have to cater for one type of visitor, ie one grandchild at a time, or two together, or an elderly relative who needs to use the toilet frequently at night, then their needs can be incorporated into your layout choise fairly easily.
It gets tricky when the situation changes, ie, we will have visitors ranging from children, Grandchildren, elderly parents, or who ever it may be, then the question is how frequent will the visits be and what are the requirement of those people visiting? Or even more complicated, two separate groups of people will be using the caravan at different times.
If the answer is that you have visitors hardly ever, or it will be a once in a blue moon type of situation, then it is best to look at the type of layout that will suit you at the current time and the visitors can make do when and if they want to come because making a layout choise to incorporate the needs for people that won't be caravanning with you all that often, may make the layout you end up with not suitable for the majority of the time you will be using it, ie, having bunk beds for grandchildren that come once a year.
If you will be having different types of people using the caravan then this is where you will have to decide on the correct ballance for your needs and look at your layout choise with that in mind.
If, as stated above, you have a set of specific people you need to cater for then again, you can start to think about the dynamics of how you can fit those specific people into your layout choise, do you need bunk beds, a center washroom so both parties can use the facilities without disturbing the other and so on.