I know. I make all models in wings. I use tricks with "tripled" edges and hard edges.

http://www.renderosity.com/mod/bcs/photos/prodimg16/product_image_full_160344.jpg

But if you want create huge polygons - not table but house wall it can generate weird artifacts. It is not a problem if you divide 1 wall for 4 parts, but if you must divide number of walls in number of houses (for example street) you can have very high res scene ;)