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San Jose's Richard Meier-designed city hall: To Leed, or Not to Leed


That was the question before the San Jose city council: whether 'twas nobler to suffer the slings and arrows of certifying its Richard Meier-designed city hall, or to avoid a sea of troubles and simply build it 'green.' Ay, there's the rub.




San Jose, California's third-largest city (after Los Angeles and San Diego), enjoys a robust population of almost one million and the idyllic climate of Northern California—300 sunny days a year on average, with a mean temperature of 70 degrees in July and 50 in January. It's also home to the largest concentration of high-tech expertise in the world, with 6,600 tech companies employing more than 254,000 people within city limits.

Both of these factors—climate and high-tech—played a role in the design of the city's newest civic building, the $345.6 million San Jose City Hall complex, designed by Richard Meier & Partners to take full advantage of wind, sun, and the latest thinking in sustainable design and energy-efficient technology.

Given San Jose's position as the capital of Silicon Valley and its documented sensitivity to protecting the environment—as early as the 1980s, the city developed award-winning recycling, water conservation, and wastewater treatment programs, well ahead of most U.S. cities—there was pressure on the Building Team to create a city hall worthy of its place in the pantheon of America's new generation of green buildings.

Yet, despite the structure's striking design and the architect's sensitivity and response to local climatic conditions, San Jose chose not to apply for Leadership in Energy and Environmental Design certification from the U.S. Green Building Council for its most prominent civic institution. All this, despite the city council's own policy, adopted in 2001, requiring all municipal buildings larger than 10,000 sf to meet a standard of LEED Certified.

Why did San Jose's municipal leaders turn their backs on LEED? And what does their action say about the viability of the LEED program as it moves into its sixth year? Before we get to those issues, let's look at what the Building Team—the Los Angeles office of Richard Meier & Partners; structural engineer Englekirk & Sabol, Los Angeles; MEP engineer Arup, Los Angeles office; and the contractor Turner Devcon—achieved.

The centerpiece of the complex is an 18-story, 530,000-sf "ultra-thin" office tower—only 68 feet in width by 255 feet in length. A nine-story rotunda, a wing for city council chambers and restaurants, and a planned parking structure round out the complex. But it is the super-slender structure that sets the environmental agenda for the complex.

Slender and light

The design team—which included Richard Meier himself; Michael Palladino, the project's lead design architect and a principal in the firm's Los Angeles office; Meier principal James R. Crawford; Meier project manager Tim Shea; and Rob Steinberg of associate architect Steinberg Architects, San Jose—achieved the desired thinness for the office tower by moving the elevator core from the center to the west side of the building to allow for an elongated rectangular floor plate. Traditional squarish-plate office buildings usually have a central core that creates a symmetrical building with open space on either side of the core. That space reduces the penetration of daylight.

By moving six elevators outside the floor plate and connecting them to the tower's west side, the design team was able to use the uninterrupted, long, thin floor plate and put high-performance exterior glazing on the two long sides. Coupled with 9.6- to 11.5-foot ceilings, the windows bring daylight into virtually every room of the building.

 
The new San Jose City Hall is shielded from the sun by an adjustable brise soleil (left) that allows radiant heat in during the colder winter months and keeps the heat out in the summer.

"We took daylighting to an extreme here, using it in as many places as possible," said Palladino. "By making an ultra-thin building we're able to bring more daylight into more space than the typical floor plate. It had to suggest where San Jose is—at the leading edge of developing technology."

The daylighting strategy uses high ceilings and the narrow floor plate to allow natural lighting and cross-ventilation. Exterior and interior shading devices can be adjusted to block radiant heat in the summer and allow it in to heat the building in winter. High-efficiency motors and other energy-efficient mechanical systems are utilized throughout the complex to minimize operating demand. A programmable building automation system allows systems and equipment to respond to the employees' building use patterns. A dozen 20-foot-tall poles spray a fine mist across the courtyard and into the rotunda to cool it.

The tower's operable windows also have long, narrow ventilators that can be opened to cool offices naturally. The air-conditioning system automatically shuts off in any area with open ventilators. A brise soleil shields the building's west side from overheating from direct sun on glass windows in the summer and lets the building use radiant heat in the winter.

"The screen is connected by dowels placed with louvers attached to the curtain wall," said Crawford, of Richard Meier & Partners. "It lets in low-angle sun in the winter to take advantage of the lower sun and its radiant load."

Most floors are nearly identical to the others, a seemingly static design that, in a counterintuitive way, actually provides flexibility. The similarity allowed for easy movement of offices and the "churn" (turnover) of employees' work spaces.

Bracing for impact

Making the tower so thin and tall in a seismic zone required sophisticated structural work by Englekirk & Sabol Structural Engineering, Los Angeles. The dual-bracing system uses a steel moment frame with concrete shear walls that extend from the foundation to the roof and book-end the structure on the north and south ends. The steel moment frame—steel beams that resist horizontal movement where a solid shear wall cannot be located—stabilizes the area between the bookends. "You couldn't build a building this thin without using this combination," said Palladino.

Thomas Sabol, of Englekirk & Sabol, explained that the shear walls are connected to the building through a series of coupling beams that unite them with the steel frame and the rest of the building. The precise placement of these beams creates the stability needed for such a narrow building.

With Meier's ultra-thin, ultra-tech design, plus the complex's many other sustainable features (see sidebar below), the Building Team is quite confident that San Jose City Hall could have earned 33 points and Silver status under LEED for New Construction. "In many areas, we went far beyond LEED's requirement for making a green building," said Palladino. "Naturally ventilating a high-rise building is not in their criteria. We thought we should use outdoor air temperature to create a comfortable environment because it makes sense for the climate the building is in."

Why, then, did the city council ignore its own policy, adopted in 2001, requiring all city buildings of more than 10,000 sf to be LEED Certified?

Timing was one factor. The project was already in the design pipeline when the green building policy was approved. Even so, many civic leaders and Building Team members still thought the city should have honored its new policy.

Money obstacles also intruded on the politics of the situation. Former mayor Al Ruffo took the city to court to stop the complex from being constructed, arguing that the city broke the law by using redevelopment agency money for the project. (The suit was dropped when the city repaid the redevelopment agency $50 million for the land.)

In 2002, a historic preservation group sued to stop construction of the parking garage to save the 1894 Fox-Markovits building, designed by Louis Lenzen, that stood on the site and would require demolition. The court dismissed the lawsuit but the delay caused the parking structure to be rebid, costing the city $2.5 million and moving the completion date back a year. The Fox-Markovits building was demolished and the parking garage is now expected to be completed by next May.

Controversies over cost overruns have increased the price of the complex since it began construction in 2002, earning it the nickname "Taj Gonzal," after Mayor Ron Gonzales.

David Vossbrink, Gonzales's spokesman, has acknowledged that increasing costs contributed to the decision to exempt the project from the LEED policy. Deputy city manager Terry Roberts said that contractual issues also intervened. "While our commitment was to do everything to make it sustainable, we decided for various reasons not to go for LEED certification," he said. "Since we started this project before the policy was passed, the contractor obligations that would have to happen under LEED didn't get included."

 
The rotunda (in front of the office building) was designed to be the the public meeting place of the complex.
Although there is no USGBC plaque on the wall of city hall, Roberts maintains that the project is just as good as LEED Silver: "Essentially, we think we have the same result."

But the USGBC holds that without third-party verification, no building can truly be considered sustainable, no matter how obvious its environmental features may be. "If you don't certify the building, how do you know?'' said the USGBC's Taryn Holowka. "Some of the features of the building may be obvious, but to truly reap the benefits of green building, you need to have third-party verification."

Roberts said that the complex documentation process required by LEED, more than the cost, was the main factor in not applying for certification.

Speaking for the U.S. Green Building Council, Holowka said that the lengthy documentation required by LEED is a common complaint that the nonprofit membership organization is trying to address. The first major changes to the LEED process in five years will be unveiled this month at Greenbuild in Atlanta. Holowka said these changes include online application instead of the current written-only applications, instruments of service that align LEED more closely with documents that are necessary for building code applications, and an online workspace wizard to guide users through the process.

Some officials within San Jose city government feel that applying for LEED certification would have been worth the USGBC fee (usually $7,500 for buildings larger than 300,000 sf, not including the cost associated with gathering the documentation or hiring consultants to do so), considering the building was designed to be sustainable with or without LEED.

"Those of us who believe in this felt we should push the envelope instead of just giving lip service to it, because I think we're going to pay for it in the end," said city council member Linda J. LeZotte. "It's just silly to do all this and not have it certified."

"They didn't go for LEED Silver, but the city was diligent in measuring against a LEED Silver program," said Arup MEP engineer McKinlay. "With the energy savings and water conservation achieved, we believe the project could easily qualify for LEED Silver."

The city has decided to have a third-party commissioning agent investigate and determine if, and at what level, the building would be LEED-certified. Deputy city manager Roberts said the city is hoping to pick the commissioning agent soon and know the building's LEED points by the end of the year.

Only when the city receives its commissioning report from the independent third party will any decision about future certification for the San Jose City Hall be made. "We want to be convinced of where we are with respect to LEED," said Roberts. "We want to know, for our own information, how green we are." BDC


  

The rotunda is cooled on hot days by a system that blows water in through 20-foot “misting” vanes in the City Hall plaza and lets hot air out at the oculus. The rotunda also uses a radiant cooling/heating floor system. Illustration: Richard Meier & Partners

Rock and roll under the glass dome

The 110-foot-high glass-domed rotunda for the San Jose city hall complex presented its own special challenges. With 1,032 pieces of Viracon clear-insulated architectural glass (with low-e coating) held together by cables and stainless steel compression members, the trick for securing the rotunda was to allow more movement, not less, so that it could sway in an earthquake.

Each pane of glass is supported by a silicon-glazed "spider" joint. The joints are closer at the bottom of the rotunda and farther apart at the top of the dome. Cables and compression members connect the suspended glass to the concrete-filled steel ribs of the structure. The open rotunda has only stairs and partial floors, so the 10-story height of the building needed to support only the glass walls. By allowing only lateral drift, the spider-joint/cable system prevents the glass panes from colliding.

"The cable and joint system and a section of the dome were tested in a lab, and it performed up to earthquake standards," said James R. Crawford, a principal with Richard Meier & Partners. "We also did peer review on the rotunda."

As the most open and inviting structure of the complex, the rotunda will be used for exhibits, dinners, and other city events. "It makes a statement that this is a civic place," said Michael Palladino, also of the Meier firm.

A misting system cools the dome in the summer. Dozens of 20-foot-tall poles spray a fine mist into the rotunda with help from prevailing breezes. Sliding doors on either side of the main entrance let breezes in. The raised oculus at the top of the dome allows warm air to escape the building.



 

Project Summary

San Jose, Calif.

Building Team

Architect: Richard Meier & Partners

Associate Architect: Steinberg Architects

Owner: City of San Jose, Department of Public Works

Structural engineer: Englekirk & Sabol

MEP engineer: Arup

General contractor: Turner Devcon Joint Venture

General information

Levels: 18 (tower) 10 (rotunda)

Size: 530,000 sf, 285 feet high

Construction cost: $345.6 million

Construction time: 21 months

Project engineer: 'San Jose City Hall's sustainable features would qualify for LEED Silver'

Bruce McKinlay, PE, project manager for MEP engineer Arup, believes that the San Jose City Hall complex would qualify for LEED Silver (33 points). Here are his thoughts about the sustainable features of the complex:

Daylighting and energy

"There's a balance that has to be struck between allowing light in and also offsetting solar heat gain on this particular project to begin with," said McKinlay. "So Arup went through a very interactive process with Richard Meier to evaluate the benefit of external shading devices that were installed (on the tower and the rotunda) versus the energy savings." As an engineer working in the state of California, which demands such high energy efficiencies on the building systems, you have to go the extra step of looking for other ways to achieve energy efficiency through taking advantage of natural daylighting and advanced building facades that offset solar heat gains, he said.

Customized cooling

Two chilled-water air-handlers on each floor (one at each end) are interlocked at the middle to provide flexibility and redundancy for maintenance or changing loads. The floor-by-floor approach allows the city to isolate floors and sections of floors that are occupied more or less continuously (such as upper floors where the mayor and the city's lawyers are located), as opposed to the bottom two floors, which are public customer service spaces with higher occupancy and more ebb and flow. The systems can respond to high occupancy and add more air or heating when there are long lines of people.

The council chamber auditorium has varying occupancy and electrical loads to handle lighting, filming, and attendance of meetings. An underfloor displacement system was created with air delivered through the steps of the raked seating.

McKinlay said these systems are very effective from an energy and indoor air-quality standpoint, because the air is delivered at a higher temperature at the occupied level than it would be with an overhead system, so the mixing is much more efficient. The air is delivered at low velocity, with the displacement system relying on buoyancy created by the bodies in the room. "The system reacts naturally to higher occupancy," said McKinlay. "Fresh air is delivered where you need it."

Outside air can cool the council wing for longer periods of the year because it is delivered at 65 degrees F, instead of 55 F for conventional HVAC systems. Since the system is cooling only the occupied portion of the space, the air in the upper portions of the wing can be allowed to warm up, thus reducing the energy load.

The council wing also houses variable-air-volume systems that serve other portions of the building.

Keeping the rotunda airy

The innovative air-conditioning system of the rotunda added to the complexity of the project.

Working with Richard Meier, Arup engineers used a proprietary software program that accounts for the position of the sun at different times of the year, the effect of the sun through the glazing on the space, and the effect of that on occupants' comfort. Once a baseline was found through thermal analysis, the spacing and size of the rotunda brise soleil were set. This created the optimum position for both comfort and aesthetics.

With most of the solar radiation taken out at the envelope, the MEP engineers had to deal with heat buildup from the solar radiation that did penetrate the interior, especially for a building designed for multiple functions and occupancies.

"We installed a radiant cooling/heating floor system to address indirect solar radiation," said McKinlay. "It's a series of hard, plastic tubes that run in a serpentine pattern within the floor slab. We'll control that slab temperature (warming or cooling) through constant adjustment of the radiant floor."

Six air-handlers can be brought online at various load requirements. The complex exceeds Title 24 energy efficiency requirements by about 18%, said McKinlay.

Systems that control the flow

The chiller plant system has a variable primary system that changes the amount of chilled water in the necessary systems for load requirements. All air-handling, chiller, and pumping systems have variable speed drives; in fact, the whole complex uses high-efficiency electric chillers at 0.57 kW/ton with no CFC refrigerants and high-efficiency heating boilers with low-NOx emissions of 25 ppm.

"Probably the biggest impact for energy conservation comes from controlling or reducing the flow of fluids," said McKinlay. "Whether it's water or air, controlling that flow to precisely the load you need at the time is crucial."

Demand-control ventilation was used in the public spaces to monitor and control flow of carbon dioxide in the tower, council wing, and rotunda.




© 2009, Reed Business Information, a division of Reed Elsevier Inc. All Rights Reserved.




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