I am trying to generate a polygon layer representing the built up, urban areas of the continental US using data from the National Land Cover Database. I have been able to generate a pretty good approximation of the densely urban areas buy reclassifying, resampling, making a polygon out of the raster, etc...but cannot capture the more suburban areas where houses are interspersed with vegetation. I came across the "Delineate Built Up Areas" tool, which uses a polygon layer of building footprints to generate a built up area layer around the buildings, based on distance between the buildings and number of buildings. I was hoping to use this, along with my polygon layer previously created, to generate the built up areas, but I keep getting results that only delineate the really densely impervious areas. Any ideas?