In the latest sign of the construction boom happening around California Avenue, Palo Alto planners are considering a proposal to demolish the Olive Garden building on El Camino Real and replace it with a three-story development that would be four times as dense as the existing structure.

The proposal by prolific architect Ken Hayes calls for merging two parcels at 2515-2585 El Camino Real and building a 40-foot-tall development with 13 residential units, office space and retail on the ground floor. It would be just down the street from another development proposed by Hayes: a four-story office building that would go up on a currently vacant parking lot on the corner of Page Mill and El Camino Real.

While Hayes' proposal for 2755 El Camino Real initially sought zoning exceptions through the controversial -- and now suspended -- planned-community zoning process, the Olive Garden project would conform with existing zoning regulations.

Much like nearby developments -- such as the block-long mixed-use project at 3159 El Camino Real, around Equinox Gym; the recently approved office development at 385 Sherman Ave.; and the three-story building replacing the old Club Illusions at 260 California Ave. -- the proposal for 2515-2585 El Camino Real illustrates the untapped potential of existing zoning.

While zone-busting planned-community projects have borne the brunt of community ire (as evidenced in last year's referendum over a housing development on Maybell Avenue), the Olive Garden property shows that the building boom around California Avenue needs no zoning exceptions to proceed. Because it complies with existing zoning, the project in many ways epitomizes the constraints the city faces in its efforts to limit office development and address the parking problems in its two busiest commercial districts -- downtown and California Avenue.

The project would be located on the east side of El Camino Real, between Sherman and Grant avenues, on two parcels that would be merged. The two parcels are currently zoned for "neighborhood commercial" and "community commercial" use, which allows things like shopping center, supermarkets and mixed-use projects.

The ground-floor restaurant would share the space with offices, while the 13 apartments would occupy the second and third floors. There would also be offices on the second floor, according to project plans.

The building front would parallel El Camino Real and a plaza would face Sherman Avenue, the application states.

Though the building density at the site is almost certain to increase, the project's design is still evolving.

On Nov. 20, the city's Architectural Review Board held a preliminary review for the project, which by definition includes no votes, and offered a mixed response.

Chair Randy Popp called the building too "horizontal" and "monolithic," though he acknowledged that the city's height limit severely restricts an architect's ability to pursue a more vertical organization. Though he focused the bulk of his comments on the project, he reserved some criticism for the city's 50-foot height limit, which drops to 35 and 40 feet in certain zones that abut residential neighborhoods.

"The height limit is a disaster for architecture because you just can't articulate the building in the right way with the buildings that we have," Popp said. "It's terrible."

Other board members also expressed some concerns with the look and feel of the proposed development, which board member Alexander Lew said has some similarity to the controversial Alma Village development.

Lew said he is concerned that the building will be "too oriented toward the back and the parking." He also said he likes other recent developments, including the Equinox Gym project and College Terrace Centre, better than the one proposed for the Olive Garden site.

Catherine Ballantyne focused on the building context and suggested that Hayes consider reorganizing his site plan. She also questioned whether the proposed building really fits in with its surroundings.

She noted that the six-story building directly across El Camino Real is a "massive concrete structure" and asked whether the city has a responsibility to somehow "balance" that structure with whatever is built at the Olive Garden site.

"I wonder if this building, as it's proposed, is the right building for El Camino right there, considering its mass and the way it's contextually integrated," Ballantyne said.

At the same time, the board generally had good things to say about Hayes' site plan and his proposal to include the plaza. Though board member Kyu Kim suggested that the office area at the corner of Grant and El Camino Real be made more "open to the public," he ultimately called the proposed development "aesthetically pleasing" and "a good project."

Popp also praised the organization of the plan, including entry points, plaza and parking layout, though he stressed that many architectural details need to be refined.

"Aesthetically this feels massive and undefined in some ways," he added.

The project will need to undergo a formal review by the architecture board and a site and design review by the Planning and Transportation Commission before it gets the green light. Hayes is expected to return to the architectural board some time in the next few months with a revised proposal.