it really doesnt work like that in Spain. The associations say the US has with what a suburd is, and of suburban life, does not translate to Spanish city planning. A better word for "suburb" in Spain would be "outskirts" of city—somewhere you might be pushed to for financial reasons. They are often urbanised areas of cheap apartment blocks, and if rural, not in a fancy way, e.g. large spacious houses. The discussion on this thread is coming from a cultural misunderstanding.

There are of course also very nice houses around cities, and rural ones out from that, but they rarely characterise suburbs in Spain (Barcelona is an exception I've noticed, and Madrid has some satellite towns and cities North of city that are very plush, though not the suburbs).