I'm a bit confused. Is this model for Poser? Poser does not seem like a very practical program for final scene composition and rendering. My first instinct would be to place this building into something like Bryce, where it can sit on a proper terrain, with plants, fog and atmosphere. So to get this into Bryce, let's say, will all the textures need to be manually retextured one by one?

"An Example is worth Ten Thousand Words"