One thing to remember is your model does not have to be a single unified mesh. Things in real life are made up of separate pieces.
Breaking the model into smaller pieces allows you to localize the heavy geometry needed to hold edges. The resulting seam lines add a level of reality to the model.
For instance, put a simple square hole in the wall and then break the window into components like the frame, the sashes, styles, and such. Each part can have its own level of detail and you can focus on the parts individually without worrying how edges required just to hold that parts shape will affect the rest of the model.
While on the subject that is supposed to be one of the advantages to sub-d modeling. You can increase the subdivision level locally. However, Maya's subd tools are so sub standard that I find them nearly useless.
As an example you can spend hours creasing and adding localized division levels and then need to convert back to polygons for some reason and all your subd modification are lost and you have to do them all over again.
"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675
Last edited by ctbram; 09-11-2010 at 06:40 AM.