Timber frames can be enclosed in many ways. The most popular method is to apply SIP panels (Structural Insulated Panels) to the exterior of the frame for both the walls and the roof.SIPs are pre manufactured panels that come in 4’-0” widths by whatever length is required. They consist of an OSB exterior sheathing, rigid foam insulation in the center and either sheetrock or OSB for the interior surface. There are several types of foam used. Legacy prefers an EPS foam (Styrofoam). There are several manufacturers that supply the SIPs, and more information can be found on their web sites. The SIPs are extremely energy efficient.
Another popular enclosure system is building a standard 2×6 wall on the outside of the timber frame and either using spray foam or fiberglass insulation.
Other methods include cord wood and straw bale enclosures.