Here in Arizona basements are almost unheard of, and if you're lucky enough to have one, you'll still need supplemental A/C running through most of the year to keep the basement cool enough for long term wine storage. When someone talks about their "wine cellar" here, what they are really talking about is a wine cooler or refrigerator of some type.
My wine cellar is comprised of three ~50 bottle wine coolers, along with a refrigerator set to the highest possible temperature, and a freezer set to 61 degrees via an external thermostat. This provides storage for roughly 250 bottles, a small oak barrel, and several carboys.
Room temperature in central Arizona hovers around 78 degrees for much of the year in most homes. This is just too warm for long term storage of most wines. In my experience, lighter, fruity wines can be noticeably over-the-hill after as little as 6 months when stored at room temperature.