I did some more research, and eventually went with creating helpers for the view:

inside admin/index

echo($viewHome->header());
echo($viewHome->render('home.php'));
echo($viewHome->footer());

inside admin/category/add

echo($viewCategoryAdd->header());
echo($viewCategoryAdd->render('addCategory.php'));
echo($viewCategoryAdd->footer());

So header, and footer are now set as helpers for any of the admin module views.

Each of the helpers is creating an instance of a view, with a render call.

Please let me know if anyone can think of a better / more appropriate solution, or if you feel it is not right to use the helpers in such a way.

Thank you

Alon