These ultra-insulating panels—made of oriented strand board (OSB) with either expanded polystyrene (EPS) or polyurethane foam sandwiched between them—usually range from four-by-eight to eight-by-twelve feet and can be used for walls and roofs. Seville gives an overview of SIPs.

PROS:

• Strong (thickness ranges from 4.5 to 12.25 inches)

• Extremely good insulation. With traditional walls, wood studs reduce insulation value. SIPs are large, solid panels that maintain a constant R-value.

• Create a better air seal than a wood-frame house. SIPs have fewer seams so there are fewer opportunities for air transfer between inside and outside.

• Quick to erect on site.

• Foam-filled SIPs are low in toxicity and are blown in using ozone- safe hydrocarbons.

• As they become more popular, they’re more readily available.

CONS:

• It may be hard to find contractors familiar with SIPs. (Issues such as installation and wiring require some previous experience.)

• SIPs are made to order, so you need very accurate measurements and careful design.

• Good for building a new home where you have control over the site, but more complicated for renovations.

• Take a minimum of two people to install.