Need help for estimate cost

I am writing a paper on a proposal for restrooms installation in our preschool classrooms. May anyone please give me a total cost estimate for the four child-sized restrooms insatallation. There's already an existing five-stalled, adult restroom outside the building, and it's about 10 meters away directly to the walls of the classrooms, where the children's restrooms could be perfectly installed. The gap in between the classrooms' wall and the adult restroom is a complete space, so there's should be no problem in setting up the connecting pipes, I think.

Could anyone please tell me how exactly this restroom installation inside our classrooms be possibly done? Thanks.

You need to call a few plumbing contractors and get them to bid it.

You can't supply us with enough information to tell you as there are to may variables that can only be seen with the eye and or blue prints.

Sounds like you may need a set of engineered / architectural prints also.

cost

The cost depends on the location of the drain and water lines, the type of ground that has to be dug through, the cost of labor in your area, how the addition will be built, the quality of fixtures that will be used, and the code requirements in your area as to the complexity of the required piping. None of this is addressed in your posting, and all of them require someone local to actually view the site.