I haven't read too far into the story, so I don't feel like I can write a full review--I'm still gathering my impressions and trying to see where the manwha will go.
But, I'm writing this because I really recommend trying Birdcage Manor out regardless!
The first thing that will strike you is the clean, gorgeous art. It's not like typical manwha art, which exaggerates aestheticism, but it's drawn with the same appreciation for beauty and detail. The result is very refreshing and devourable art.
The other thing that will draw you into Birdcage Manor is the story. You get a particular feel from the story; it's different. I can tell that the author had intention going into this, although I'm not sure how'll she do in maintaining it.
The manwha treats its subjects (the residents of a run-down apartment complex) specially, giving them subtle but significant attention even if they're just side characters. It does the same with the main characters: the focal point of the manwha is the stories behind the characters. But unlike other works with this focal point, it tries to incorporate these stories with the action of normal flow of life rather than examining backstories through arcs or other devices. The approach gives the manwha a sort of sleepy feel, like how you might feel when you ponder about the various lives of the people residing in your apartment building.
This interesting effect is counterbalanced by the romantic action that develops between Kizuna and Asai and sort of Yuki. I really think the approach the author takes with examining her characters has the ability to work well with the romance, and she seems to be tacking towards that as well, using Asai's past to affect his relationship development. However, it's a matter of balance, which takes art and skill. I feel like the manwha has a predisposition to get absorbed in the progressing action and botch up the pacing, leaving the potential of the focal point not fully developed.
The characters, though, will have you smiling even if the romantic progression seems to get a little weird. Kizuna has a real personality and Asai's apathetic charisma actually has some depth to it, unlike the normal deadpan character. Yuki adds dynamism to the interaction between the three characters. And really, it's just those three characters; the rest are side characters. I like this, and I hope that their personalities are well-developed before or if any other characters emerge.
Overall, Birdcage Manor seems a really interesting, unique manwha. Regardless of whether or not it's executed as ideally as I like to envision, the premise is different and generates an enjoyable read. It'll be interesting to see how it turns out.