Concord, Edgemont, Chadd's Ford, and Newtown are as close as you'll get to exurb type areas in Delco. Its very built up mostly, like Nassau County on Long Island.
Montgomery has more exurbs than appear at first blush from the voting (i.e. besides the Salfords, Worcester, Douglass, and Franconia). The Hannovers, Pottsgroves, Fredericks, Providence's, Hatfield, Towamencin, Limerick, etc. are all exurbs. We need to do better out there.