By the way, there is much heat in discussions about housing prices and urban development, but very little light and much misunderstanding. A good rule of thumb is simple: If you don't see any reliable sources being cited, there's a good chance that the assertions aren't true or don't encapsulate the most important parts of the supply-demand picture.
The real reason Dallas and Houston are growing fast while remaining affordable is because we can sprawl forever.
The Dallas area has no natural boundaries whatsoever; there are no mountains and no coast, nothing to stop development from sprawling out constantly. I was born in 1984, and I've lived in Dallas my entire life. I've seen the suburbs balloon in size like you wouldn't believe; and I'm not just talking population here, but area. The idea that we have continuous suburban development extending all the way north to Prosper (and soon Celina) blows my mind. Suburban development used to peter out in the northern half of Plano, and honestly southern Plano wasn't fully built-out either (there even used to be huge unincorporated enclaves in Plano).
Another is business culture; companies, especially tech companies, have largely chosen to avoid the central business district and instead locate their offices in the edge cities [0] and the boomburbs [1]. Blame historical happenstance: this phenomenon was entirely thanks to two companies who decided in the 1950s to locate their offices in Richardson instead of Dallas. One was Texas Instruments, which was founded as a startup in Richardson (none of the founders were native Texans, oddly enough), and the other was Collins Radio (now Rockwell-Collins), an established company from Iowa who decided to put their Texas campus in Richardson. Between the two of them, anyone in North Texas who wanted into the tech industry worked in Richardson. After that, the founders of TI decided to start a technology-oriented university so they can grow their own talent right there in Richardson. Soon, they handed over the university to the state, who promptly renamed it the University of Texas at Dallas (despite it actually being in Richardson). Since then, UTD has become the most prominent school for engineering and computer science in the entire southwest (when I went there, the phrase "MIT of the southwest" was bandied about a lot), cementing Richardson as the home of the tech industry in North Texas.
I find it interesting; housing prices actually have spiked in the Dallas area thanks to an unexpected surge of demand (I expect prices to go down soon, as new sprawl catches up to the demand), but Richardson is still one of the most affordable cities in the Dallas area, and it's still recognized as being one of the best cities in the US to live. That combination of affordability and quality of life is rare; usually, the two are inversely proportional. You can still find a good house in Richardson for under $300k, and if you look carefully, you can go below $250k.
Now, I don't know too much about Houston, but it's pretty low on natural boundaries. Sure, it's not too far from a coast, but that's only to the south, and right now Houston's sprawling north and west. No mountains, either. I don't know much about how the business culture evolved, though.
Houston and Dallas: http://time.com/80005/why-texas-is-our-future/ or, somewhat less usefully, http://www.forbes.com/sites/scottbeyer/2016/08/31/why-is-aus....
The big problem is zoning: https://object.cato.org/sites/cato.org/files/serials/files/r... as it was implemented in the '70s: http://www.amazon.com/Zoning-Rules-Economics-Land-Regulation...
By the way, there is much heat in discussions about housing prices and urban development, but very little light and much misunderstanding. A good rule of thumb is simple: If you don't see any reliable sources being cited, there's a good chance that the assertions aren't true or don't encapsulate the most important parts of the supply-demand picture.