Sometimes zoning adjustments make sense for housing towers

The proposed 40-story tower at Folsom and Spear streets, designed by Jeanne Gang for developer Tishman Speyer, would have a ground floor of shops. ProEXR File Description =Attributes= cameraAperture (float): 20.120001 cameraFarClip (float): 1000.000000 cameraFarRange (float): 1000.000000 cameraFov (float): 82.344612 cameraNearClip (float): 0.000000 cameraNearRange (float): 0.000000 cameraProjection (int): 0 cameraTargetDistance (float): 200.000000 cameraTransform (m44f): [{0.226423, 0.0990836, 0.968976, 410.347}, {0.974029, -0.023033, -0.225248, -292.992}, {1.86265e-009, 0.994813, -0.101725, 68}, {0, 0, 0, 1}] channels (chlist) compression (compression): Zip16 dataWindow (box2i): [0, 0, 4999, 2812] displayWindow (box2i): [0, 0, 4999, 2812] gamma (float): 1.000000 lineOrder (lineOrder): Increasing Y pixelAspectRatio (float): 1.000000 screenWindowCenter (v2f): [0.000000, 0.000000] screenWindowWidth (float): 1.000000 tiles (tiledesc): [64, 64] =Channels= B (float) G (float) MultiMatteElement_1-3.B (half) MultiMatteElement_1-3.G (half) MultiMatteElement_1-3.R (half) MultiMatteElement_4-6.B (half) MultiMatteElement_4-6.G (half) MultiMatteElement_4-6.R (half) MultiMatteElement_7-8.B (half) MultiMatteElement_7-8.G (half) MultiMatteElement_7-8.R (half) R (float) VRayAlpha.B (half) VRayAlpha.G (half) VRayAlpha.R (half) VRayGlobalIllumination.A (half) VRayGlobalIllumination.B (half) VRayGlobalIllumination.G (half) VRayGlobalIllumination.R (half) VRayLightSelect.B (half) VRayLightSelect.G (half) VRayLightSelect.R (half) VRayLighting.A (half) VRayLighting.B (half) VRayLighting.G (half) VRayLighting.R (half) VRayReflection.B (half) VRayReflection.G (half) VRayReflection.R (half) VRayReflectionFilter.A (half) VRayReflectionFilter.B (half) VRayReflectionFilter.G (half) VRayReflectionFilter.R (half) VRayRefraction.B (half)... less The proposed 40-story tower at Folsom and Spear streets, designed by Jeanne Gang for developer Tishman Speyer, would have a ground floor of shops. ProEXR File Description =Attributes= cameraAperture (float): ... more Photo: Studio Gang Photo: Studio Gang Image 1 of / 4 Caption Close Sometimes zoning adjustments make sense for housing towers 1 / 4 Back to Gallery

As San Francisco officials decide in coming months whether to allow a proposed tower near the bay to rise higher than zoning allows, remember this: One thing worse than bending the rules for developers is to self-righteously declare that such rules should never be changed.

And if the city wants to make the creation of low- and middle-income housing a true priority - as should be the case in our economically stratified region - flexibility in terms of urban design can be a valuable tool.

But such flexibility must be the exception, not the default mode.

These complicated policy issues might seem unconnected to architectural aesthetics, but they're inseparable from last week's initial presentation of a 40-story tower designed by Chicago architect Jeanne Gang for a site on Folsom Street one block inland from the Embarcadero. Her concept has a rhythmic tumble of abstract bays down each side of the slender shaft, soft diagonal cascades in masonry tiles.

The proposed height of 400 feet is less than at least eight other towers that are allowed in the plan for the two dozen blocks surrounding the new Transbay Transit Center, which is set to open in 2017. But it exceeds the 300-foot zoning for the site bounded by Folsom, Spear and Main streets.

Despite this, planners who oversee the Transbay area for the city recommend that full studies be done of the taller version of the proposal as well as a design that fits within current zoning. The citizens advisory committee for the district endorsed the dual track on a 7-1 vote at the Thursday meeting.

The rationale from the city's point of view involves those two staples of local political debate, housing and money.

The proposed tower and an adjacent eight-story building together would contain 390 residential units, 139 priced at below-market levels. In the tower, 64 of the 315 condominiums would be reserved for middle-income buyers. The low building would contain 75 units, all affordable.

Taller tower makes sense

The latter building would be the same however tall the tower rises. But it also requires a $19 million subsidy - which happens to be the amount that developer Tishman Speyer has offered to pay for a city-owned parking lot needed to build the project. Keep the tower at 300 feet - 100 feet lower than the desired height - and the bid drops to $14.6 million.

A skeptic - and skepticism of developers is a good rule of thumb - would say the city should insist on the higher price for the lower tower. Dare Tishman Speyer to take a walk. Except that if this happens, nothing gets built. Instead of 139 affordable units, or the 114 envisioned in the smaller proposal, we'd have a parking lot and a two-story 1950s warehouse with towers on three sides.

Here's the other thing: On this particular block, the taller tower would be preferable in terms of city-building.

Directly to the east is the brick-covered Gap headquarters, a broad, thick presence from 2001 that tops off at 275 feet. It's better to take a dramatic step up with a more slender and light-toned tower, as Gang proposes, and let the existing wall of Embarcadero buildings stand visually on its own.

Awkward initial design

The architectural challenge with the 400-foot scheme isn't the rippling facade, but the beginning and end. The initial design is awkward, with the masonry tower seeming to sit heavily on the glass ground floor, rather than lift off from the sidewalk. At the top it just stops, as if the shaft had been sheared in one clean stroke.

We don't need a cowlick of skin-deep bays continuing past the roof and curling toward the heavens. Still, there's work to be done.

The challenge for City Hall decision makers is to realize that if there's anyplace where zoning adjustments make sense, it's on a block and in a case like this.

Gang's tower could be an attention-getting but genuinely attractive counterpart to its neighbors, an accent rather than an overwhelming presence. The city, meanwhile, can steer subsidies and financial resources to other affordable housing sites that don't have a deep-pocket benefactor next door.

The perils in development trade-offs are the irreversible impacts that can harm the landscape we hand to future generations. There are plenty of places in San Francisco where drawing a hard line is necessary.

In the emerging high-rise neighbor along Folsom Street, by contrast, a little more pizzazz - and residential diversity - is the right way to go.