Startup's prefab homes aim for zero energy bills

Startup's prefab homes aim for zero energy bills

Prefabricated housing seems an unlikely ally in the fight against climate change, but a new San Francisco company is setting out to construct factory-built homes that create as much energy as they use - reducing greenhouse gas emissions associated with operating buildings.

Zeta Communities, which is headquartered in South of Market and owns a manufacturing plant in San Leandro, is close to completing its first "zero energy" townhome in Oakland and is working with a developer on a proposed 30-unit studio apartment building in Berkeley.

The firm plans to build segments of housing units indoors and ship them to development sites for assembly.

Energy-saving features include extra-thick windows, dense insulation, efficient appliances and a monitoring system that manages temperature and ventilation and tracks electricity use. Warmth in the house is used to heat incoming air, and recovered hot wastewater helps warm shower and sink water. Solar panels generate new energy.

Many other U.S. companies build energy-efficient prefabricated single-family homes. But Zeta hopes to capture the market for multifamily townhomes, lofts and apartments that are affordably priced and complement environmentally conscious smart growth, planning in which dense development is concentrated near public transit.

"What allows us to build housing at a competitive cost with zero energy bills is that we're doing it in a factory where we have very efficient design and production and cut down on waste," said Naomi Porat, Zeta's CEO.

Zeta's plan coincides with recognition by the state and federal government that housing is a major contributor to global warming. But while green building experts say Zeta's idea has promise, it nonetheless faces hurdles - both environmental and economic.

It is estimated that homes are responsible for nearly 22 percent of annual energy use in the United States. The operation of all building types represents 50 percent of carbon dioxide emissions - resulting from the production of energy needed to heat and cool buildings and run lights and appliances. With those statistics in mind, the U.S. Department of Energy and the California Public Utilities Commission recently announced goals that all new homes be zero-energy by 2020.

Government prodding and research have spurred several energy-saving homes, and communities are emerging in California, Colorado and other Western states. The developments use power generated from nonpolluting sources - such as solar, wind and underground geothermal systems - and feature energy-saving homes.

But so far, the new neighborhoods mainly consist of single-family dwellings, according to Ren Anderson, head of the residential research group at the National Renewable Energy Laboratory, a Department of Energy lab. And it appears that most zero-energy condo communities have been built on site, rather than prefabricated.

One of the biggest knocks on prefabricated housing is that completed segments must be shipped (typically by truck) to a property for assembly.

"Having to ship housing works pretty well if you don't have to go far, but shipping can take too long and cost too much and negate some of the (environmental benefits of the) building's design," Anderson said.

Another reality is that the energy saved in a Zeta townhome or development will depend, to some extent, on location and the developer's interest in reducing energy consumption.

And because the concept is relatively untested, questions remain about how many developers will embrace modular construction.

Zeta, which stands for Zero Energy Technology and Architecture, obtained several million dollars in venture capital funding and, according to Porat, is in discussions with developers on other potential projects in Northern California.

A Zeta equivalent of a two-bedroom live-work townhome would be sold to developers for approximately $258,000 per unit, including shipping, installation and mechanical systems and appliances, Porat said.

She believes that her product's energy draw could be 40 to 60 percent less than a comparably sized standard home and may work best in urban settings, where buyers are attracted to dense housing and are inclined to reduce energy use.

Oz Erickson, a longtime San Francisco developer who has completed a number of infill projects, said his firm looked into using Japanese-built prefabricated, modular housing several years ago but found that it was too expensive.

Zeta's prices might make them more competitive, he said.

"Modular homes have very quick construction times, which can save you money," he said. "The green elements could cut down on the very high costs of heating and cooling."