By hyping an amped-up urban center, Mayor Nickels' new proposal to scrap 1989's voter-approved limit on downtown building heights seems like a smart and bold attack on Seattle's provincial attitudes about growth and density.

If only. While Nickels' pitch for taller buildings downtown is being spun as a daring move, it actually represents a retreat in the battle to upgrade this city into a real one; a fatal cave-in to Seattle's dominant Not-in-My-Backyard class during this 2005 reelection year.

Nickels wants to raise downtown heights to accommodate a whopping 75 percent increase in downtown density (that's great!), but he's scared to demand comparable zoning upgrades in other Seattle neighborhoods--like allowing detached granny flats, multi-family housing, and more mixed-use development in the majority of the city. It's great to promote a dense, mixed-use, transit-minded, 24-hour urban center, as Nickels is doing by proposing increasing height limits downtown. But by focusing on the city core in isolation--that is, without connecting a pro-density strategy downtown to an overhaul of building codes citywide--Nickels is failing to address the biggest choke on Seattle: the dominance of single family zoning. Of the available land in the city, a stunning 75 percent is set aside exclusively for single-family housing. It's no wonder Seattle built just 40 percent on average of the new units needed to meet its density goals over the last 10 years, with some neighborhoods hitting a lowly 5 percent of new housing goals.

Without the majority of this city doing its fair share to promote and accept density, the lopsided emphasis on downtown will end up undermining Nickels' stated aims to lower housing prices, create more housing options, and put a belt around sprawl.

Consider: Nickels' plans calls for 10,000 new housing units downtown and 30,000 new jobs downtown. Obviously, all those people working downtown aren't going to be able to live downtown. But without demanding more density in the rest of the city at large, Nickels is floating a recipe for disaster. The limited supply downtown compounded by a neighborhood movement that has walled off the rest of the city will spike housing prices through the simple laws of supply and demand and drive downtown workers out of the city.

It's smart election-year politics. Nickels is throwing a bone to downtown developers who, by the way, have contributed handsomely to his 2005 campaign, and he's appeasing the NIMBYs by sparing the neighborhoods. However, it's dumb urban planning.

josh@thestranger.com