My in-laws love their new home in Arizona. When I visited them last month, I began to understand why. After a lifetime in Connecticut, their new community, Sun City Grand, is basically a retiree’s paradise. Located in Surprise, a 40-minute drive from downtown Phoenix, it has four golf courses, two community centers, a day spa, arts-and-crafts facilities, a lifelong-learning center, lap pools, and pickleball courts. The grounds are beautifully maintained, and the layout of their three-bedroom is spacious and livable. The place is fabulous, and it terrifies me.

Sun City Grand is one of dozens of wildly successful, age-restricted (55 and older) retirement communities built by Del Webb, a subsidiary of Pulte Homes. Building homes for hundreds of thousands of older Americans is a seemingly altruistic enterprise, like knitting sweaters for orphans, but unfortunately someone forgot to build towns to go with the houses. For all its amenities, Sun City Grand lacks essentials of urbanism like throughstreets, offices, and retail. Don’t get me started on the houses themselves: Green design? Forget about it.

The same failings stick to the other walled and gated developments I saw in Surprise (age-restricted and otherwise). The nation’s fi ve biggest builders— Pulte, Centex, D.R. Horton, KB Home, and Lennar—are all at work there, and the city that they’ve collectively built isn’t worthy of the term. Surprise amounts to a giant strip mall, a hard-sell wrapper for the builders’ massive, isolated housing developments. My in-laws drive five miles to buy milk, and during a three-day visit, much of it spent behind the wheel, I didn’t see a single bus.

The population of Surprise has grown from 4,000 to 100,000 in 25 years. That kind of growth only happens when local government rolls over. Either development takes control, or it takes its money elsewhere, leaving conscientious architects and planners with little room to negotiate.

For builders, control means adhering to a simple, inviolable set of planning principles—a formula that’s been handed down, and watered down, for generations, starting with Frederick Law Olmsted’s 1869 plan for Riverside, Ill., and winding up in the parking lot of a Walmart near you. Simple hasn’t been good for Surprise, and it’s been terrible for America, because simple, in this case, means shortsighted. The formula’s got to change.

While we’re busy pillorying investment bankers, automakers, and politicians for their roles in the current economic mess, let’s make room in the stocks for builders. Not only did they push their product on millions of families that could ill aff ord the investment, turns out the nation can’t aff ord it either. Profi teers in the home building industry have left the U.S. holding a steaming bag full of unsustainable communities.

The President’s proposed stimulus package, with all its provisions for new infrastructure and green energy, could set the nation’s place-making practices on a new course. Let’s hope. Detroit is imploding because it refused to improve automobile fuel efficiency in the face of overwhelming evidence that oil supplies are dwindling. The home building industry has eff ectively done the same thing—not at the scale of a vehicle, but at the scale of a city. If only more builders had embraced Smart Growth, or even converted to the Church of the New Urbanism, before the bubble burst. I’d take a Celebration, Fla., over a Surprise, Ariz., any day.