Hey, don't make us huntyour normal screenshots, we don't all have 3d glasses lying around.
Also, it's kind of silly, but I just wanted to throw out the Luigi's Mansion actually has some great examples of already-simplified detailing of similar architecture and interior space. Especially for trim and atmosphere in general. For as few actual "things" as they have and dealing with such low poly stuff, they managed to create really filled-out and lively spaces. I think wainscoting would be a big help in that hallway.
Right now, my biggest issue is that the space doesn't feel like a house in any way, and has some awkward proportions and structures inside it as a result (the size disparity beween the rug/mantle/sofa/doorway in in the living room, for example, or the random ramp/stairs of the newest shot.) The theme still feels a little shoehorned into the space provided by Valve, but I hope you come up with some clever ways to hide these issues and make the space feel more believable.