See all the glowing lines? Those show where the geometry is being broken up by normal solids. You should func_wall as much detail as you can. Things like that sign up there, all the supports for the lights, the flourescent lights, the tables, the taps... Every little detail should be turned into a func_wall. Speaking of taps, you should try to limit your use of those and the bottles. Sometimes you have to sacrifice realism for gameplay.
Also, you might want to consider ditching a lot of those smaller things. I noticed these little doorknobs on the cabinets, and they were like 2 units wide! NOBODY will care if you get rid of stuff like that. Hell, they'll be glad!
You should also strongly consider using models in place of much of your detail. There's this website (which I lost the address of) that has tons of Half-Life prop models you can download. If anybody knows the place I'm talking about, please provide the address. I remember it wasn't in English.