Q. Re- prior question 1985 - You also mentioned that the other side of a mechitza is not part of the shul, and people davening there are not part of the minyan. However, in many shuls men daven there when there is no women and the Rabbis seem to agree. Are they all incorrect?
A. Shulchan Aruch (O.H. 55: 18) rules that if some of the minyan's ten participants are inside the shul, while some are in the azarah, they do not complement each other (and there is no minyan). Mishna Berura (52) explains that even if there is a mechitza between them if they see each other they do complement. He adds that it is obvious that the ones who stand on the ezras noshim and there is a mechitza separating them from the rest, but there is a window and they can see each other, they become part of the minyan.
On note 57 he quotes Pri Megadim's opinion, that when the participants see each other, even if they are in two separate houses, they complete together the minyan. Mishna Berura adds that some Poskim disagree, and therefore only when in need you may be lenient.
Poskim also disagree if they have to see each other clearly (Kaf Hachaim 77, Eishel Avraham 195), or it suffices if they can see, albeit not clearly, as through a net like curtain. (Tov Ayin 18: 31).
Horav Shlomo Miller's Shlit'a opinion is that it depends as each particular case is different.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit'a