PROVO -- A Provo couple is being recognized as pioneers of the local green home movement.
Green homes are built to be energy efficient, and today they are increasingly popular. But just six years ago, when Carol and Lawrence Walters built their New England farm-style home, they struggled to buy the materials they needed and hire crews that knew how to use them.
Their home is heated by the sun during the winter and cooled in summer using a passive solar design, and an array of 30 solar panels means this couple pays nothing for electricity -- in fact, they provide electricity for the public grid. But these technologies are not where this couple broke new ground.
Their home was one of the first, if not the first, in Utah to be built using structural insulated panels, referred to as a "SIP home." SIP is something like a Lego, only made of huge blocks of styrofoam sandwiched with chipboard. A SIP is 10 inches of pure insulation, and when complete, the house is more or less completely airtight.
That's a big deal when you consider that the average home has so many air leaks that it is the equivalent of having "a 10-foot-wide hole in the wall," Carol Walters said.
Having such a tight seal is part of the reason this home can be heated by sunlight in the winter, with light coming through special windows designed to be highly insulating. The light warms a travertine stone floor, which in turn heats water inside pipes under the floor. The heated water expands, moving throughout the house, bringing the cool water back to the stone floor to be warmed. When there is not enough sunlight to properly warm the water in winter, an on-demand water heater system automatically kicks on, fueling the radiant heat.
"Eighty percent of the heat in the house is just from direct sunlight," she said.
One heat exchanger for the radiant floor, another for the vented air in the attic and carefully calculated thermal mass are other technologies the house employs to use as little energy as possible.
What did all this cost? Less than you'd expect -- and even fewer dollars if it were being built today, thanks in part to the Walters and others who pioneered SIP construction locally.
When the couple building their home in 2007, the housing bubble was at its height. The average cost of building a new home in Provo was $130 a square foot, compared to about $110 today. The Walters spent $140 a square foot. Today, the same home could be built for about $75 per square foot -- and is, all over the state, especially in Park City, according to Scott Dwire, the couple's builder. Those costs do not include the solar array, which the couple added just two and a half years ago, after Provo approved an ordinance that allowed residential solar systems to get credit from the electric company for the energy they put back into the grid.
"The reason we produce more electricity than we use is because we are careful about what we put in the house -- light bulbs, fixtures," she said. "We hang our clothes to dry. We try to make sure lights are off when we leave a room."
Even their television is plugged into a special box to stop it from "sipping" electricity when turned off. Most televisions, computers and many household appliances quietly "sip" electricity even when they are off, which runs up the long-term bill.
One downside of being pioneers is that not everything works according to plan. If they could do it over, the couple said they would raise the downstairs ceiling to 9 feet from 8 feet and lower the cathedral ceiling upstairs. They would use porcelain tile instead of imported natural travertine, which hasn't held up well to wear. They would not have installed bamboo floors upstairs, because of concerns about VOC gases released by the glue used to make the flooring, and they would have added more thermal mass to the upstairs. They are now in the process of bringing in special wall materials from Germany to add thermal mass, which will cool the upstairs better at the height of summer.
There are a couple of weeks each summer when the upstairs reaches 80 degrees, which is uncomfortably hot. Adding thermal mass to the walls would cool the upstairs naturally. The house has no air conditioning by design.