One of the main reasons why model train beginners tend to start off with a 4’x8’ HO train layout is because building it is very easy and it also provides enough flexibility to grow your layout. 4’x8’ plywood sheets are readily available and do not take up an incredible amount of space. It is better to start larger then too small. It is just like getting your haircut, once its cut you cannot change it but if the barber starts off cutting it off slow, you can manage and customize it as you see fit
