Sept. 17, 2006 12:00 AM

Metropolitan Phoenix's housing market is "somewhat" vulnerable to a real estate bubble.

But that's not necessarily a bad thing, because if home prices dip a little, affordability will climb and the area's growth has a better chance of continuing.

People and companies move to Phoenix because the area has relatively affordable housing for the West, not because the Valley is "hip and cool" or because it has the best education system.

That was Joel Kotkin's message to the Valley's real estate executives last week at an annual real estate seminar called "Evolution: The Valley of the Sun, a Look at Future Growth."

It wasn't the typical real estate forecast citing past figures and predictions for how rosy metro Phoenix's future will be. Speakers took a hard look at where the Valley was headed and what could halt its long-cherished growth.

Kotkin is an authority on global, economic, political and social trends and an Irvine senior fellow at the New America Foundation. Unlike many national experts, he knows Phoenix and not just the older cities of the East and Midwest.

"Lower home prices are a necessary correction for Phoenix," Kotkin told the crowd.

As the real estate market slows, causing some cooldown in the overall economy, he said Phoenix must stick to the basics that made it grow: affordable housing.

Many in the audience and on the panel with Kotkin agreed.

Grady Gammage, real estate attorney and a firsthand observer of Arizona's evolution, said that for years, people have debated what's behind metro Phoenix's growth. Cheap housing or jobs? He thinks it's cheap housing.

The session was sponsored by the Urban Land Institute, Valley Partnership and Lambda Alpha International, three groups that have upped the level of discussions about development and growth in the Valley.

Mobile property

The tiny town of Mobile is one step closer to becoming a Valley suburb.

Veteran home builder Garth Wieger has teamed with some other well-heeled investors to buy more than 9,000 acres in the area, known more for its landfills and Lufthansa training field than houses. Wieger already controlled about 1,000 acres in Mobile, so this new group has more than 10,000 acres altogether.

The deal involved a couple of different transactions, but a group called Sonoran Valley Property led by Wieger paid about $320 million to buy more than half the private land in Mobile. That single price makes its one of the biggest land deals in Arizona history.

Specifically, the land is between 71st and 115th avenues from east to west and runs from 2 miles south to 3 miles north of Arizona 238.

Buckeye isn't the only southwest Valley city that can annex. Sonoran Valley Properties is talking to Goodyear about annexing its Mobile land.

There were a lot of players involved in this deal.

Wieger's partners in the project are Joe Porter, former president of Denver-based Design Workshop, and Tim Keenan, formerly of Sunbelt Holdings. Elliott Homes Inc. sold the 9,000 acres.

Land sales have slowed along with home building, but this deal was a bonanza for several brokers, including Nate Nathan and Dave Mullard of Nathan & Associates and Tom Argiropoulos Jr. of John Hall & Associates.