Foam Homes -- Polystyrene-And-Plywood Sandwiches Can Make A New House Sturdier Comfier And Snugger

Terry Kirkpatrick is proud to live in a foam house. It feels strong, looks good and has become somewhat of a tourist attraction.

Just the other day, a group of about 20 building contractors from Japan dropped by to visit his unique three-story waterfront house on Lake Sammamish.

There they heard him describe the virtues of a house constructed using structural insulated panels, or SIPs (basically compressed styrofoam in a plywood sandwich). Panel houses, he said, are easier to build, affordable, use less wood and are quieter and more airtight than a traditional stick house.

"My heating bill in May was only $21.81," said Kirkpatrick, who despite his apparent waterfront-affording affluence, must make ends meet on a middle-school counselor's salary. He can afford to live on the lake because the property has been in his family since the 1940s.

But what Kirkpatrick seems to like best is the feel of his house. He used 6-inch-thick panels on the exterior walls and 8-inch-thick panels on the ceilings and floors.

"It's not going anywhere," he said with a smile.

Other "panelized" houses and buildings are starting to pop up around the Northwest and across the nation. They include:

-- The new headquarters office in Issaquah for Shirey Contracting, which built Kirkpatrick's house and others in the area.

-- The 22-unit Emerald Courte apartments in Puyallup is using SIPs manufactured by Fife-based Premier Building Systems. Their panels also are going into a number of other new buildings, including the new Boy Scouts headquarters in Tacoma, said Premier's Kevin Hayes.

-- On Whidbey Island, architect Jean Steinbrecher specializes in designing log houses with panel roofs, a popular use because they can be quickly installed and thus protect the rest of the house from rainy weather.

-- In Michigan, a new 200-house development is making news by offering buyers a choice of either traditional stick or SIPs construction.

Orchard View Estates is being built by Crosswinds Communities, known for helping revive inner-city neighborhoods by building new condos that resemble row houses. This Crosswinds project, however, looks like conventional subdivision houses out in a country location.

The two types of houses look the same from the outside. The big difference is inside the walls.

Viewed from the top or bottom, these walls look like a sandwich. The center of each is four inches of white foam - extruded polystyrene. It's enclosed between two sheets of heavy exterior-grade plywood.

The sheets are built from thin layers of shaved wood, bonded together with glue. It looks like the typical processed wood you might see on any house that doesn't yet have siding, but it's actually thicker and stronger. A single wall panel can be up to 8 feet high and 24 feet long.

With SIP houses, much of the labor takes place in the factory, where each wall is custom-built for each house, and window and door holes can be cut in.

When the walls reach the home site, they are glued and nailed together. Either at the factory or at the home site, tunnels are drilled through the foam plastic core to let electricians and plumbers install wiring and plumbing.

SIPs get high ratings from the National Association of Home Builders and the energy-conscious magazine Environmental Building News, which last year devoted a cover story to them.

Carpenter Jeff Wilson, who is working in the Orchard View project, likes the look of houses built with SIPs. Sighting down a wall's long, straight line, he says, walls usually aren't like this in new houses today. They tend to bow in or out.

"In the old houses, with plaster, you'd get that straight look," said Wilson, but today it's usually missing. "Our lumber isn't the way it used to be."

The consensus is that SIPs do a very good job of meeting a house's basic needs. They give:

-- A higher level of insulation than the usual fiberglass batting.

-- An air-leak seal with fewer seams than house wrap.

-- A structure that's two times as sturdy as conventional 2-by-4 stick building.

They do this at an affordable cost. And SIP houses go together quickly, with less labor in the field - a boon given today's shortage of skilled house framers.

Energy-conscious groups love SIPs. Even the thinnest SIP wall - 4 1/2 inches thick - has a robust insulation value of R15.

And many people like SIPs because they can be built with recycled wood or young scrub trees, lessening demand for old-growth lumber.

To its promoters, SIPs have a bright future because they address many of today's concerns.

"Skilled labor is disappearing," said Donna Bade Shirey, co-owner of Shirey Contracting. "Saving natural resources in construction, not depleting our forests, energy-efficient homes are all vital issues."

And as Wilson put it: "Being carpenters, we go through a forest in a year. I like these things. I like to save as many trees as possible."

Seattle Times staff reporter Bill Kossen and the Detroit Free Press contributed to this report.

----- Q & A -----

Q: Aren't these houses too airtight?

A: It's much better to build a very airtight house, then add a little inexpensive ventilation, than to struggle with a leaky house.

Q: Aren't we damaging the ozone layer when we manufacturer that extruded white foam?

A: No, 95 percent of SIPs are made with extruded polystyrene (EPS), which does not have ozone-damaging by-products. If you encounter the rare SIP that says it's made with HCFCs, avoid it. Its manufacture does damage ozone.

Q: Doesn't the extruded foam make a good home for carpenter ants?

A: It would, so many SIP makers include an insecticide. The R-Control brand infuses its foam with a relative of the boric acid that many people sprinkle to kill ants. It is harmless to humans.

Q: Doesn't all that glue in the wood panels give off gases that can hurt chemically sensitive people?

A: It could if the glue is formaldehyde-based, so the consumer should check. Some SIP makers use formaldehyde glue on the exterior panel and a different glue inside. Others use only a water-based glue. Once the water dries, what's left is an inert plastic.

- Detroit Free Press