Sandy could land Utah's tallest building - make that buildings.

On Tuesday, the burb's City Council approved a new arts-and-culture land-use zone that allows towers up to 600 feet tall, paving the way for a 40-story high-rise, about 550 feet, near 10100 South and Interstate 15. That's just the first phase of The Proscenium, which calls for two additional 30- to 40-story buildings.

The LDS Church Office Building in downtown Salt Lake City is currently Utah's tallest, topping off at 28 stories and 435 feet. In Lehi, world-renowned architect Frank Gehry has plans to best that height with a 450-foot, five-star hotel.

But The Proscenium could dwarf even those architectural giants.

Plotted by Orem-based developer Scott McQuarrie, the $560 million project's first phase contains a 2,700-seat Broadway-style theater, 500-seat "showcase" theater, performing arts school, offices, a hotel and 36 condos in or around a 40-story high-rise. It's expected to debut in fall 2011.

Sandy's new 600-foot rule applies only to buildings that qualify for the new arts-and-culture zone within the central business district, meet certain conditions and win the OK of the Planning Commission. Otherwise, buildings in Sandy's commercial core can only reach 140 feet, or about 10 stories.

In a separate measure, Sandy is crafting an ordinance that would raise the 140-foot limit to 200 feet, or about 15 stories, throughout the city's central business district, which spans the I-15 corridor from the South Towne Exposition Center near 9400 South to the South Towne Mall near 10600 South. The density boost is on hold until the city finishes an overhaul of its transportation master plan.

It's likely the arts-and-culture zoning - and soaring height allowance - will only ever be used for The Proscenium.

City Councilman Dennis Tenney promised a concerned Sandy resident on Tuesday that high-rises would not be sprouting in her neighborhood.

The new zoning "is specific to this [Proscenium] property - period," Tenney said. "It truly has the opportunity to become iconic in terms of putting Sandy on the map, not only in Utah but in the Intermountain area."

Council members Stephen Smith and Linda Martinez Saville both said the project's towering new heights gave them "heartburn," but joined in unanimous votes to approve the new zoning and apply it to The Proscenium.

Smith visited Chicago last week and noticed a skyscraper that looked similar to the ones planned in Sandy: The Trump International Hotel and Tower.

"Every day I'd stand next to the [Chicago] River and look at that building and try to figure out what it would look like in Sandy," Smith said.

He could get that chance in 2011.

rwinters@sltrib.com

Sandy's Planning Commission now can approve heights up to 600 feet within the city's new arts-and-culture zone in the central business district. To win approval, a project must:

* Meet silver standards set by the U.S. Green Building Council's LEED (Leadership in Energy and Environmental Design) program. The project does not have to certify.

* Contain five or more uses, such as residential, office, retail, entertainment and education.

* Include a regional arts venue.

* Have buildings with distinct ground, middle and top levels, including an attractive, pedestrian-friendly street level.

* Produce an economic impact report.