Structural insulated panels (SIPs) are often used in timber frame building. They are panels consisting of a rigid insulated foam core sandwiched between two structural boards. SIPs are strong, cost effective and energy efficient.
While the cost of SIPs themselves may be higher than the comparable materials used in conventional framing, the labor savings to install them is significant. The energy savings is generally thought to have a 3-5 year return on investment, making the long term cost of the house lower.