ASK THE EXPERTS: SIPs and Window Suppliers

Structural insulated panels (SIPs)
Structural insulated panels offer a quick method of creating a well-insulated, efficient building envelope.
Structural insulated panels (SIPs)

I read the article in HP153 on financing energy-efficient homes (“Getting the Green for Your High-Performance Home”) and was interested in getting more details about the home built with structural insulated panels (SIPs). What company supplied the SIPs, and how were they installed? I know that the homeowners acted as the general contractors, but it still seems that some training and experience would be needed to install the panels.

The article also mentions that the house uses high-performance, argon-gas-filled, fiberglass windows, which is exactly what I want for my new home. What kind of coatings do the windows have, and what are their U-factor and solar heat gain coefficients?

Teresa Hopkins • Medford, Oregon

Glad you like our home, Teresa. My husband Shawn and I are really happy with its thermal performance, which can be attributed directly to a well-insulated, tight envelope; high-performance glazing; and the home’s passive solar orientation. 

Our SIPs are from R-Control, a Montana-based company that makes the panels from expanded polystyrene (EPS) insulation laminated with oriented strand board structural sheathing. We chose 8.25-inch-thick wall panels (R-29.3 to 31.6) and 12.25-inch-thick roof panels (R-44.7 to 48.3). (Since our house was built, I’ve been interested in another SIP product—Agriboard—which replaces the EPS with compressed wheat straw, and uses no-urea-formaldehyde-added OSB with nontoxic adhesives. The company is not currently manufacturing panels, but plans to start in Q1 of 2014.)

We hired an experienced local builder to oversee the SIPs placement and coordinate the boom truck, which maneuvered the sections into place. He was the only SIPs-trained person on site. Other than that, we had four experienced framers and four others—some with more building experience than others—to help set the walls and roof.

The panels come numbered from the factory, which also provides a corresponding plan showing the relationship of the SIPs to each other. One at a time, each panel was secured to the boom truck’s lift with a hefty strap and lifted off the truck. The boom truck driver “flew” the panel, while the ground crew helped put it into position over the sill plate, which had been coated with sill sealant. A couple of smart whacks with a sledgehammer was all it took to correct any errors in positioning. The ground crew then fastened the panel to the sill plate using a pneumatic nail gun. The exterior walls for our 1,452-square-foot home went up in about eight hours; the split shed roof took a little longer—about 12 hours—but that also included the framing of a supporting wall and clerestory.

Our Serious double-paned, fiberglass-framed windows were manufactured in Colorado. We “tuned” the windows, specifying the highest SHGC windows they offered for the south face of the house. While Serious may no longer offer these fiberglass units for residences, other manufacturers still do. Check out the window selection tool at When I searched for double-glazed, high solar gain, low-e, argon/krypton gas windows with a “thermally improved” nonmetal frame, eight different manufacturers turned up—Accurate Dorwin, Fibertec, Marvin, and Pella were among those offering high-performance “solar” windows. Happy building!

Claire Anderson, Home Power managing editor

Comments (1)'s picture

There is another company called Agriboard ( My brother and I used to work for them. They are in North Texas, west of Dallas.

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