An ambitious restructuring of all building zones within Salt Lake City - a project under way for the past four years - would set the stage for orderly and well-patterned growth and deserves to be approved.

For nearly 70 years, since zoning laws first were introduced, the city has been allowed to take shape, adapt to changing times and reform itself again and again without the modern tools planners need to ensure a quality community.The city is remarkably attractive and vibrant despite this, but potential problems abound.

Parks are designated as residential zones, meaning they someday could be converted to subdivisions. High-rise areas downtown are governed by the same commercial designations as businesses elsewhere in the city, with no thought to mass-transit incentives or other unique high-density needs. Aging neighborhoods are suffering as homes are divided into duplexes or multiple apartments.

The rewritten zoning laws, which will be considered at a final public hearing at the City-County Building Tuesday, would address these problems. New terms would be added to the city's zoning lexicon. Parks, cemeteries, golf courses and other recrea- tion areas would be designated as open-space zones. A downtown zone would control the density and height of inner-city buildings and would cap the number of parking stalls allowed in each new project. In many of the city's older neighborhoods, the ratio of single family homes and duplexes would be preserved at its current 8 to 2 level.

More important, the rewrite would push future downtown development to the west and encourage high-rise apartment construction to the east, stopping the gradual erosion of the some of the city's most cozy urban neighborhoods to commercial intrusion.

Parts of the plan may backfire. Businesses may balk at downtown parking restrictions and choose instead to build in the suburbs. Rents may rise as inexpensive duplexes become scarce.

But the plan takes these possibilities into consideration and requires the City Council to meet every other year to assess the need for changes.

A citywide zoning rewrite is a massive and complicated project. With Salt Lake City posting its first population gains in more than 30 years, the timely approval of this plan would be a fortuitous example of governmental foresight.