この部屋はシャワーだけでお風呂がないんですが。
=> "This apartment only has a shower but no bathtub"
This would be what I think this sentence says contentwise. I also think it could be a viable translation, but the way its expressed confuses me.
First, I'm not sure if I understood the overall syntax of the sentence correctly. It seems to me that 部屋 is the topic here, but I dont think that it's the subject of the following clause.
"Concerning the apartment, with the shower only there is no bath."
Second, I'm struggling with the connection of
シャワーだけで
and
お風呂がない
Since I assume that the sentence says that there is a shower, but no bathtub, attaching both nominal phrases (shower and bathtub) to the predicative ない gives me a headache.
And here, the third unclarity comes into play.
What is this で? Is it the particle I was assuming? If so, are there any phrases omitted as well? I just can't imagine how shower and bathtub shall be connected to ない, so there must be an omitted verbal phrase expressing the existence of shower. Its either that or maybe you can explain how japanese can express the existence of something with a verb that's actually stating the non-existence of something ^^