Net Zero Zenith

by Jonathan McGaha | January 28, 2013 12:00 am

Metal panels give largest U.S. net zero community sustainable design

The University of California, Davis West Village community comprises 205 acres with 662 apartments, 343 single-family homes, and commercial and recreational facilities. It’s situated just west of the main campus in Sacramento, Calif. The campus consists of three primary developments: the Ramble apartment complex, Viridian apartment homes and retail space, and The Center recreational facility.

It is the largest planned net zero energy community in the United States.

Solar-reflective roofing from Rocklin, Calif.-based Sonoran Roofing Inc., radiant barrier sheathing from Davis, Calif.-based CP Construction West Inc., and 40,000 square feet of metal wall, roof and canopy panels are helping it achieve this. The sustainable design of the community limits energy consumption, enables energy production and contributes to a healthy environment. It is on track to demonstrate, for the first time, that net zero energy is practical on a large scale.

From the project’s inception, in addition to its energy emphasis, project architects wanted authenticity and aesthetics. There is nothing cookie cutter about this campus. “This was a really big piece of property with nothing on it yet; we went in and did the village square first with our seven buildings,” says Tilly Whitehead, project manager and architect at Studio E Architects, San Diego. “Critical to this project was, we wanted it to look authentic. We wanted it to look like people could inhabit it, like it belonged there. When you go out to the village square, it feels authentic; like it hasn’t just been transplanted there.”

Metal’s efficiency

Metal was instrumental in creating campus buildings that could achieve the project’s goals at a reasonable cost. “Metal came into this equation when we created ventilated façades on the southern and western sides of our building,” says Eric Naslund, FAIA, principal architect, Studio E Architects. “That is where in the upper central valley of California, especially in the summertime, you get some really hot days. We suspended the metal away from the framing. It’s vertical corrugated metal, so it acts like ‘little chimneys’ all the way up the façade. Ventilated at the bottom and ventilated at the top, the metal creates a shield or protective device against the building and provides some ventilation behind it. The heat load does not build up on the wall, and then later on it can reradiate into the unit all night long because it has been storing energy all afternoon.”

The Ramble apartment complex features more than 11,500 square feet of 24-gauge, 7/8-inch corrugated panels from Metal Sales Manufacturing Corp., Louisville, Ky., in four custom colors: Green Drop, Glowing Firelight, Swedish Blue and Mustard Yellow. “We chose Metal Sales panels because they bring an interesting aesthetic to the exterior of the buildings,” says Michael S. Todd, project superintendent with CP Construction West, the general contractor. “Metal Sales matched the colors we needed, which makes the buildings ‘pop.'” Viridian is a multi-use facility that houses retail space on the first floor and three stories of apartments above. The first level is expected to house retail stores, restaurants, and university research and development offices. It features more than 18,000 square feet of 22-gauge, 7/8-inch corrugated panels coated with custom colors Gypsum and Zentury

Brown. The exterior is also covered in stucco, creating a striking contrast with the panels from Metal Sales. Canopies are clad with 24-gauge, 18-inch flat Vertical Seam roof panels in Champagne Metallic. All of the panel colors from Metal Sales are listed with Energy Star, improving energy efficiency and reducing the amount of energy needed for cooling. The panels also have a long life span, are 100 percent recyclable, and contain a high percentage of recycled material, which contributes to LEED points.

Net zero energy design

The California Public Utilities Commission has called for shifting all new residential construction in California to net zero energy by 2020 and all new commercial construction to net zero energy by 2030. UC Davis West Village is well ahead of schedule. As a net zero energy development, UC Davis West Village generates as much energy as it consumes. “The way to do that without spending exorbitant amounts of money is to drive the energy load down on the buildings that you have,” says Naslund. “Be smart about how you arrange windows and shade things. You do everything you can do to reduce energy consumption, then you try to generate as much energy on-site. The sweet spot is when you’ve produced as much energy as you need.”

Campus buildings are equipped with energy-efficient appliances, as well as customized window awnings with moveable wooden slats allowing residents to control the amount of sun that enters their rooms. Large ceiling fans cool living spaces. Residents can use the web to monitor energy use. A smart phone app lets residents turn off lamps and plugged-in electronics remotely. Energy-efficient exterior lighting fixtures, indoor occupancy sensors and daylighting techniques help the community use about 60 percent less energy than if standard lighting had been used.

Another way West Village plans to produce its own green power is with a planned waste-to-energy bio-digester, an invention patented by a UC Davis engineer. It will convert the village’s garbage and waste-also referred to as “feed stock”-into energy. The technology combines different feed stocks into the bio-digester, where they decompose at different rates. They can be transformed into methane and hydrogen, and used for electricity and heat. Solar and challenges

The development taps into a 4-megawatt photovoltaic system driven by 15,000 solar panels from Sunpower Corp., San Jose, Calif. The panels are mounted on rooftops, parking canopies, sides of buildings and even the village clock tower. Saw-toothed roofs are tilted to a southern orientation, and residential halls are situated along east-west streets to maximize the “solar gain” or breeze on any given day. On sunny days, the panels generate more electricity than is needed for the site and send some back to the power grid. At night, the community pulls electricity from the grid, balancing out the excess power produced throughout the day.

When the building was being conceived, initial designs had all the photovoltaic panels contributing to one resource and residents drawing from that resource. “In essence creating a solar utility,” says Naslund. “What ended up happening as a result of government rebates and incentive programs, was individualized solar arrays, unit by unit. It went from a solar electric company, to individual seven-to-eight small ‘per-unit’ arrays.

“This created some challenges because we had to have inverters for every unit on the building, we had to do a lot to get it all to fit. What’s important is each unit now has its own dedicated array tied in through a dedicated inverter into its own electrical panel. It works almost as if it was tied into a singlefamily home with a dedicated meter and its own dedicated point of service.”

Another project challenge was when the metal panels were installed, the metal had to be detailed in such a way so it could ventilate correctly. “To capture the heat behind the metal would have been counter-productive,” says Whitehead. “We needed the top and bottom metal parts to breathe. It turned into more of a rainscreen application; that’s simple to achieve with metal. With the fascia, we had to detail it to prevent water from dripping into it, but it could still breathe.”

Todd says the size of the panels contributed to the hardest part of the installation. “We ordered fulllength panels,” he says. “With some of the buildings being four stories it took some careful maneuvering, but in the long run was well worth it.”

In the end, metal was instrumental in to the project’s success from cost, ease-of-installation, low maintenance and performance perspectives. “The character and the feel of it really tied into our ideas of these buildings feeling comfortable in an agrarian landscape,” says Naslund. “We didn’t try to make the buildings look like barns, but their look was similar to big-scale agricultural buildings that you would typically see in the upper central valley. Metal provided a sweet spot to do all these things.”

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UC Davis West Village Community, Sacramento, Calif.

Owner: West Village Community Partnership LLC, San Francisco Developer and property manager: Carmel Partners, San Francisco

Architects: Studio E Architects, San Diego, Calif., and MVE Institutional, Santa Ana, Calif.

General contractor and radiant barrier sheathing supplier: CP Construction West Inc., Davis, Calif., (303) 691-3275

Metal panel supplier/installer, and single-ply roofing: Kodiak Roofing & Waterproofing Co., Lincoln, Calif., www.kodiakroofing.com[1]

Metal wall panels: Metal Sales Manufacturing Corp., Louisville, Ky., www.metalsales.us.com[2]

Photovoltaic panels: Sunpower Corp., San Jose, Calif., us.sunpowercorp.com[3]

Solar-reflective roofing: Sonoran Roofing Inc., Rocklin, Calif.,
www.sonoranroofing.com[4]

 

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West Village green features include:

• A programmable, high-efficiency heat pump heating and cooling system
• Energy Star electric kitchen appliances and high-efficiency clothes washer
• Ceiling fans in living rooms and bedrooms
• Patio doors and over-sized windows to let the Delta breeze flow through the entire living area and provide natural lighting
• Window blinds and exterior sunshades to block direct sunlight
• Water-saving toilets that use only 1.28 gallons of water per flush and are 20 percent more efficient than required by code
• Water-saving shower faucets that use only 1.5 gallons a minute, reducing water usage by 40 percent from standard building code
• Low-flow water fixtures that depend on air, rather than more water, to generate water pressure
• Low VOC paint, and kitchen cabinets with a water-based low-VOC finish
• Living area floors made from 50 percent recycled material
• Ecoquartz kitchen countertops made from recycled quartz

Source URL: https://www.metalarchitecture.com/articles/net-zero-zenith/

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