Build Your Home With Energy-Efficient Structural Insulated Panels

Enlarge Image Image Gallery SIPs are suitable for a variety of architectural styles and cladding options. Photo Courtesy R-Control Building Systems

Builders and consumers who want energy efficiency but don’t have the means or the desire to build with straw bale or adobe must rely on improvements to stick frame materials and methods. Structural insulated panels (SIPs), enclosure systems typically made of two engineered wood panels that enclose a rigid insulating foam core, may not seem like an obvious choice for environmentally conscious builders, but they’re widely praised for offering energy and resource efficiency, construction speed, and design flexibility.

Used in place of the traditional combination of studs, sheathing, and insulation found in standard construction, SIPs are suitable for walls, roofs, and floors. The first homes using SIPs were built in the early 1950s and are still occupied today. The industry has grown most rapidly in the last decade, however, and Bill Wachtler, executive director of the Structural Insulated Panel Association (SIPA), estimates that there are now more than 10,000 SIPs homes in the United States, and more than 30 manufacturers. International demand, particularly in Japan and Europe, is also driving the expansion.

Are SIPs for You? 

SIPs lend themselves to simple, boxy design, but they also allow for design flexibility. Builders use SIPs for many different architectural styles; they work well for open floor plans because their strength and efficiency eliminates the need for excess interior walls.

Although SIPs products differ slightly, they all require similar construction techniques. Openings for windows and doors can be cut into the panel on site or pre-cut at the factory. Panel connection methods vary from engineered wood splines to steel joints, but all types are designed for rapid assembly, and panels are made with prerouted chases for electrical wires.

Proponents claim that careful planning to minimize waste makes a SIPs project as inexpensive as stick framing. If a builder works from plans designed specifically for panel efficiency and uses cutoffs from one part of the house elsewhere in the construction, costs will be much lower than dropping SIPs into plans for a traditional stick frame house. (Some companies will convert plans to accommodate panels, which they then fabricate.) For builders, the big advantage of SIPs is rapid, one-step construction of the shell, which provides savings that can trickle down to the homeowner.

SIPs are one of more than 100 environmental features in the Energy and Environmental Resource Center built by Atlanta’s Southface Energy Institute in 1996. “I’d like to see SIPs used more in production building, especially when windows and doors can be pre-cut at manufacture,” says Mike Barcik, director of technical services for Southface. “This is the most practical, efficient use of this technology.”

The downside to SIPs is that the number of contractors with experience using them is still limited. Although manufacturers claim their products are “builder-friendly,” Barcik says, “you might have to educate and train a crew.” But, says Wachtler of SIPA, “Every year it’s getting easier to find architects and builders familiar with SIPs. Interested builders and consumers can use membership in our association as a screening mechanism to find reputable manufacturers who are rigorous with testing and exceed building code specifications.”