You pretty much need at least 16GB to be able to use UE4. Sure some things work with less than that, but it won’t really be fun, especially if you use static lighting. Even when I had 32GB of RAM I often had that being completely filled while using UE4 + Chrome. Only when I upgraded to 48GB of RAM I no longer had issues with it, so 48GB seems to be “enough” for UE4.