regarding applying to live in a "girls only" building...
well, i do identify as a girl.
however, i recognize that this is exceedingly complicated.
the fact is that i'd rather live by myself insofar as that is actually possible. but, i see these units open up from time to time that are essentially basement rentals, with access to the kitchen. regarding that kitchen access, i'll point out that i already own a microwave and could afford to get a small fridge in a big enough basement. i could quite easily organize my meals so that i only need very sporadic access to the kitchen. i pretty much require my own bathroom, though.
i wouldn't apply to a boys only space, because i wouldn't classify myself as a boy - that is not the correct place for me to live, if we must live in gender categorized dwellings. but, i have applied to live in girls' spaces before, and could very well do so again.
is it discrimination if they tell me i'm not a girl and therefore can't stay there? sure. but, i'm actually willing to accept this kind of discrimination as allowable. stated tersely, i would accept the right of cis women to erect cis-female-only spaces - to a caveat.
so, if a property owner decides she wants to split her house up into rooms and only rent to cis-femaless, and the cis-females that live there agree to that, i don't think i have any place arguing against it - that would be invasive on my behalf, because we're sharing parts of the residence. but, if a cis-woman owns an apartment building and decides she only wants to rent to cis-woman, i would consider that to be discriminatory, and argue she should be taken to the human rights tribunal - and that whether she's refusing to rent to me as a trans-woman or as a cis-male is secondary to the female-only policy. this idea would apply equally well to race or orientation or whatever else. and, i believe that the existing jurisprudence actually draws the line at pretty much this exact point.
so, while i'll sue the owner of an apartment building for refusing to rent to me because i'm trans, i do not feel the same animus towards somebody running a rooming house for girls - even as i don't feel any apprehension about applying as a trans-female.
subtle enough?
i just have enough empathy - and am perhaps girl enough - to be able to understand the situation from the other side. even as a transwoman, i might not feel comfortable living in a rooming house with a transfemale at a different stage of transition. i'm trying to avoid a property rights argument, because it's missing the point - it's more about freedom of association. what i think is that it should be up to the tenants.
but, the logic collapses as soon as you start talking about separate apartments - then i go back into trans-activism mode.