Tower at C Street Adds Solidly to S.D. Skyline : Design: A new addition among background buildings ranks as one of the city’s finest high-rises, but a neighbor to the north has little to offer.

Urban designers and architects call them background buildings. They form the calm canvas against which other, more idiosyncratic signature buildings stand out.

Downtown San Diego has grown up with new buildings of both types in recent years.

Statement buildings such as the Emerald Shapery Center, with its hexagonal spires, and superstar Chicago architect Helmut Jahn’s One Great American Plaza, both on lower Broadway, bring welcomed flair to the skyline.

Several new background buildings are filling in the spaces between such bold architectural statements.

Two of San Diego’s newest of these more modest structures are the $33-million, 20-story tower developed by Los Angeles-based Cabot Cabot & Forbes on a full block facing C Street between Columbia and India Streets, and the $12 million, 12-story building a block to the north, developed by the Koll Co. in partnership with Ace Parking.

The two buildings may be neighbors, but they are worlds apart in the quality of their architecture.

Cabot Cabot & Forbes’ tower, completed a year ago, has a conservative but well-detailed exterior and an inviting street level plaza bordered by palms. It ranks as one of San Diego’s finest high-rises.

The Koll/Ace building, which opened in December, is a basic econo-box. It contains the maximum amount of leaseable space that could be built on the site, and is a tower sheathed with bland low-cost stucco and reflective glass. And, at the street level, the building has little to offer pedestrians.

Both buildings are in the Columbia Redevelopment Area, where projects are reviewed by the Centre City Development Corp., the city’s redevelopment branch. But, because of slightly different circumstances and timing, CCDC was able to have a more positive impact on Cabot Cabot & Forbes’ building.

“This was their first San Diego building, and they wanted to do an important building,” said Pam Hamilton, executive vice president at the CCDC. “We had a negotiating agreement with them because they were unable to acquire the property at first, but they finally did acquire it without our participation. Since they were originally headed toward agency involvement, I think we had more influence.”

You’d never be able to tell by looking that the Cabot building was designed by Langdon Wilson Architects, the Los Angeles company also responsible for the Wells Fargo and Koll Center high-rises on Broadway downtown, two far less successful efforts.

Contrasted with the dimly lit, claustrophobic lobbies common at most San Diego high-rises, this open-air lobby shows some fresh thinking.

Three huge openings address the C Street plaza. These, together with tall, narrow banks of windows, spill copious amounts of natural light into the richly finished, well-designed lobby, with its floors of white marble and black and green granite, and a vaulted white ceiling that seems to float ethereally over the space.

The Cabot building has a bank on the ground floor, a mini-market at one back corner and space for an additional retailer at the other back corner. These uses enliven the building’s base with pedestrian activity.

The outdoor plaza facing C Street is one of downtown’s best public spaces. For one thing, it faces the right direction--south--so that lounging lunchers can enjoy maximum sunlight. For another, courtyards at both ends of it are surrounded by stepped stone planters with ledges at just the right height for sitting.

These two basic ingredients needed for any good public space--good sunlight and seating--seem simple enough, but it’s surprising how few San Diego buildings make use of them.

Simple, well-proportioned design is what unifies this project from bottom to top.

Pale gray, precast concrete panels are gracefully combined with aluminum windows, black-granite accents and carefully placed seams and borders to achieve an exterior with classical elegance at moderate cost.

The tower, which rises from a base that includes several levels of below- and above-grade parking, is defined by vertical window bays which give tenants fine waterfront views and break the expansive exterior walls into smaller forms.

The building’s flat top received just enough attention to make it interesting: a subtle, beveled cornice marks the top of the tower, a simple period at the end of a well-crafted sentence. Other flat-topped San Diego high-rises don’t even bother with punctuation.

San Diego architects Tucker Sadler, who designed the Security Pacific Bank tower on 3rd Avenue downtown in the early 1970s, also designed Koll/Ace’s project.

The CCDC allowed extra density after the developers acquired a 5,000-square-foot parcel to the west of their building, now used for additional parking and handicapped access.

“They built their building on one site and used the extra 5,000 mainly to boost their floor-area ratio (density),” CCDC’s Hamilton said. “If that land had been included early on, there could have been a more integral design. Our intent wasn’t to have the property added in such an awkward way.”

The building occupies only the southeast portion of its block. It butts against an existing pseudo Mission-style low-rise on the southwest corner. In anticipation of another project to the north, the north wall of Koll/Ace’s building is blank. This windowless side of the building houses mechanical equipment and elevators.

For practical reasons, the entry had to be near the elevators, so visitors enter through a small mid-block lobby on Columbia, instead of near, or at, the busy intersection of B and Columbia, which would have made a more interesting location for an entry.

One parking entrance is right next to the building’s main entry, an unfortunate juxtaposition of pedestrians and automobiles.

The Koll/Ace building’s stucco and glass exterior is cheap--and looks it. The architects gave exterior walls V-shaped glass notches that rise from bottom to top in an attempt to add interest, but monotonous planes of reflective glass and bland stucco dominate.

An angular pinnacle atop the building at one corner makes another minor design gesture, but it is not visible to pedestrians, so it doesn’t do a thing to improve the building’s cold street presence. Street-level retail space is not yet occupied.

A steel-and-neon sculpture by San Diego artist Lili Lakich, mounted on a wall in the lobby, is the most interesting thing about this mundane addition to the downtown skyline.