Can tell you now, unlikely you will get it into reloaded as you most likely exceeded the amount of verts X format will allow.
19k polygon is far too much, how detailed is the building.? Screenshot will help to gauge if 19k is too much for what you are creating.If the walls is subdivided, I would suggest using a larger texture map and reduce the amount of subdivision, unless the building has lots of arches in or rounded corners, 19k is absurdly high. Could also be the way you modeled it.?
If there is no other way, slicing the model into equal parts per floor, in other words you should have 3 meshes that you can layer in the editor to create the final building.
I have managed to render a million polygons on screens without taking too much of a hit, and that includes a 100 AI running about.19K isn't bad but it's not ideal. For a building if you consider there will be other buildings around most likely, you will likely then run into problems.
Win7 pro, Intel 2500K @3.7ghz 660GTX 8gig ram 16tb HDD