The architect for 777 South Broad, the latest foray into residential construction by developer Carl Dranoff, takes pains to describe the design as an "urban" building and a "background" building. That's architect-speak for: "Don't expect exciting design."

Don't worry. We didn't.

The five-story rental development is Dranoff's first project since he gave Philadelphia the syrupy Symphony House, the architectural equivalent of a pink daiquiri, at Broad and Pine Streets. So it was with no little trepidation that we braced ourselves for the concoction Dranoff would serve up between Fitzwater and Catharine Streets, three blocks south on the Avenue of the Arts.

Though Dranoff's architect, Jerry Roller of JKR Partners, may have intentionally set a low bar for the project, which broke ground last week, he spares us the sugar overload. The renderings suggest that 777 should be a much better building than Symphony House, even if the architecture happens to be straight out of a developer's playbook.

For the exterior, Roller and his design partner, Matthew Koenig, follow the well-trod path of alternating red brick with silvery aluminum-framed windows and balconies. But unlike the notoriously cloying 32-story Symphony House, by BLT Architects, every element at 777 is there to serve a logical and effective design purpose. Whereas Symphony House changes materials and styles seemingly at whim, 777 stays on message. That message may be cliched, but it never slips into vulgar chaos.

Like Symphony House, 777 employs a two-toned quilt of masonry and metal as a strategy for making its mass feel smaller and more interesting. While Symphony House's architects were trying to camouflage bulk and height, JKR's task was to enliven a building that is a full block long, but only five stories high.

Long, low-slung buildings tend to be boring, especially to Philadelphians, who are accustomed to the visual stimulation that comes from encountering a jumble of styles, periods and materials on every block. By using vertical sections of brick and silver at 777, JKR succeeds in breaking down its long expanse into manageable bites, creating a rhythm that mimics a typical rowhouse block.

The architects even go so far as to create a slight differential in the roofline for the brick and metal sections, reflecting the irregular proportions of the city's rowhouses. By punctuating the Fitzwater and Catharine Street corners with dramatically bowed windows, they quote yet another local tradition: Those bows are descendants of the fanciful turrets found on larger Victorian townhouses of the late 19th century.

True, the architects also have thrown a bit of art deco into the rowhouse stew, with curved balconies and a stepped central marquee. Fortunately, they haven't crossed over the line into Symphony House excess.

You don't have to wander very far to find another project that trades on the city's rowhouse rhythm. Walk around the block to the recently rebuilt Martin Luther King Plaza, by Torti Gallas & Partners, and you'll see a small-scale version of 777. You've got to love the idea of Dranoff's high-priced rentals' being a rip-off of a public-housing project.

Maybe that's one reason the brick on 777 is intended to be the real deal, instead of cheaper premade panels or the ersatz horror of Symphony House's cast concrete. The Philadelphia Housing Authority managed to build with real brick on the main facades of the MLK houses. How embarrassing if the luxury building next door stinted on that crucial detail. Let's hope that Dranoff doesn't change his mind if costs start to rise, and that his architects have the freedom to choose a brick of the right heft and tone.

Of course, Dranoff probably would never have considered a luxury apartment house for Broad and Fitzwater before the Housing Authority replaced the decrepit MLK towers in 2003 with the more livable, rowhouse-style units. In a few short years, the scars the towers inflicted on the neighborhood have begun to heal and the area has reclaimed its rightful place in Center City's orbit.

It's already hard to imagine that a location so close to City Hall was only recently a no-go area. Dranoff deserves credit for recognizing its potential. The site might have been redeveloped sooner, but the Housing Authority fired the original development team, which included Kenny Gamble. Ironically, Dranoff has now taken Gamble on as his partner in this venture.

One area in which 777 improves on the MLK design is sustainability. Dranoff is trumpeting the project, scheduled to open in 2010, as the city's first green mixed-use residential building. He expects certification from the U.S. Green Building Council, but 777 qualifies largely by doing the easy stuff, such as providing bike racks, Philly CarShare spaces, low-flush toilets, and recycled carpet. Instead of having a planted roof to control storm runoff, 777's surface parking lot will be paved with a porous asphalt.

The building is less truly urban than it might have been. With the blessing of former Mayor John Street's Planning Commission, Dranoff was allowed to revise his original design to eliminate underground parking and retail spaces on the side streets. He also was given permission to interrupt Broad Street with a 20-foot-wide driveway, even though the building's parking lot can be accessed from both side streets.

It will be interesting to see whether the more pedestrian-friendly Nutter administration allows Dranoff to get away with such intrusions next time he builds on Broad.

The developer already is eyeing the southeast corner of Broad and Spruce as the site of a 50-story-plus signature tower. Maybe the third time around, Dranoff will find a way to deliver both good design and good urbanism.