If you’re thinking about incorporating eco-friendly design elements into your home, the options can be a little overwhelming: Solar panels? Greywater system? Green roof? Your answer may depend on your budget and your priorities, but according to several East Bay architects and builders, the most meaningful sustainable designs are ones that focus on energy — specifically, cutting down usage of it.
“We tend to focus quite a bit on energy,” said David Wilson, principal architect at WA Design in Berkeley. “We’re always trying to get the buildings to make as much of their own energy as possible.”
Houses in the United States use a lot of energy (about 11,280 kWh per year per residential customer), with about half the total energy use going to heating, according to the US Department of Energy. The next largest chunk — about 18 percent — goes to water heating. California, thanks to its temperate climate, is among one of the nation’s lowest energy-consuming states among residential consumers, according to the US Energy Information Administration, but the United States is still one of the world’s top overall energy consumers (behind China).
Cutting down energy use from fossil fuels is one obvious way to lessen climate change. And thanks to a new leasing model, as well as better technology, solar energy systems are increasing in popularity. As the Express previously reported, the solar industry had a record year in 2012, with a 76 percent jump in megawatts installed on rooftops.
Still, widespread adoption of solar energy is far from where it should be, said Matthew Baran of Berkeley-based Baran Studio Architecture. “In an area like this where you get a fair amount of sun, if all these new houses being built had solar panels on them, we’d have a power plant,” he said.
Reducing the amount of energy a home needs is the other main consideration, and that process begins before it’s even built. Cate Leger and her partner Karl Wanaselja of Berkeley-based Leger Wanaselja Architects try to cut down energy use in the building process. One way they do that is through the use of scavenged or recycled building materials, both traditional and non-. They have used shipping containers, which they buy from Air-Sea Containers in San Leandro, as well as used-car roofs, which they’ve scavenged from local junkyards, in some of their more inventive designs. “The shipping containers work well in this region because we have a lot of shipping containers around here and they’re very strong for earthquakes,” said Leger.
So-called “passive” design is another popular trend among builders. The concept focuses on eliminating the need for a heating, ventilation, and air conditioning system (HVAC) by conserving and distributing solar energy through improved windows, walls, and floors. Baran recommends reducing your energy needs through elements like concrete floors, which absorb heat on a hot day and emit heat on a cold one; radiant floor heating, which he said is a cheaper way to warm a home than an HVAC system; and highly reflective roofs that eliminate the need for air conditioners.
While insulation is important to energy efficiency, Leger stressed the importance of using nontoxic materials, such as blown-in cellulose insulation, which is composed of shredded newspapers and cardboard. “That’s a super-low, light footprint,” she said.
Going even further, the Passive House standard is a more stringent concept that involves making homes airtight and then circulating heat and air through a mechanical ventilation system. The concept was imported from Europe, and, according to Home Energy magazine, can reduce a home’s heating needs by 80 percent.
Architect Nabih Tahan was the first person in the United States to retrofit a home — his own, located in Berkeley — to the Passive House standard. He also started the group Passive House California, which offers classes and certifications. Tahan said there are still many barriers to making passive houses more popular in the states, while in Europe, they’re becoming much more widespread.
“We’re not used to making buildings airtight so they go way overboard,” said Tahan. “There’s a lot of products we don’t have. Our windows are really low quality compared to European windows.” He also noted that there’s a significant amount of equipment and strategy that goes into making a passive house, which could add another 5 to 10 percent to building costs. “But if you calculate the energy savings over the life of the building then it’s much, much cheaper,” he said. Since completing his home, Tahan said he’s started contemplating an even bigger picture of a home’s energy use, through its complete life cycle. That includes everything from building materials from natural resources to considering how much energy is needed to tear down a house and recycle its parts.
If Passive Homes sound too daunting or cost-prohibitive, Leger recommends that homeowners get an energy audit to figure out how they’re losing or wasting the most energy. That allows homeowners to know which steps to take next — replacing single-pane windows with double-pane ones, or fixing leaky windows, or getting insulation. (Tahan likened a home’s heat loss to a hole in your pocket: Would you keep putting money in or would you fix it?)
If you can’t afford an energy audit, Leger suggests getting a Kill A Watt meter, which gauges home power use. One thing residents don’t often consider is how much energy plugged-in appliances use when they’re not in use — the so-called “phantom load.” Leger herself discovered that all her plugged-in appliances were using up to 10 percent of her total electrical load, which she could eliminate by plugging them into a power strip and turning it off when they’re not in use. “It adds up,” she said.