I  believe there should not ...

I  believe there should not be a common formula for community toilets. It depends on the community and their customs. An European Government organization did such a project in Northern Namibia, where families traditionally live far from each other, even  in a 'village'. (There has always been enough space). For them community toilets are traditionally unacceptable, in spite of the good intention of the organizers, the toilet project was not successful. Community showers were more successful, because washing oneself for this particular community is a social event.