Really nice! I like the more abstract version of the keys -- #13 -- although they sort of look like musical notes now, but the idea is a terrific one! I would prefer a more sophisticated font.
I like 27 very much. That's more the direction I'm looking for, but a bit more like Spanish tile. This looks like an English scroll pattern. And I'd still like to convey real estate in a subtle way in the symbol, if possible.
#40 is definitely my favorite of all the ones you've done so far... really pretty! There's just a lot going on, and I don't see a connection to real estate. I'm also looking for simple, elegant.