I live in an apartment with a balcony that is fully covered by the balcony two floors above (the balconies are zig-zagged). This means that I cannot build a kosher sukka in my balcony. I don't have any other place to build a sukka instead, so if I don't build it in the balcony, I won't build one at all.
Is it preferable to build a sukka that I know in advance that will not be kosher, or to not build a sukka at all? Does a "best effort" count for anything?