Insulation (R-Value): Does your project need a low conduction (High R-value) roof and/or walls for high performance? It depends on the building type, climate, and occupancy schedule. We recommend you use Green Building Studio to answer the question. For example a house in a winter-dominated climate will benefit from higher R-value (lower U-value) constructions while a retail store in a warm climate will probably show increased energy use with higher R-value constructions. This is because improved insulating qualities will trap heat within the building, it will reduce heating demands but may lead to increased cooling energy requirements.
Metal Frame: While valued for its structural benefits and recycled-content, metal framing has the drawback of a lower assembly insulation value than a wood framed component because of the high conductivity of the metal. Also wood has a greater ability to retain moisture than metal.
Wood Frame: Wood construction offers a better overall insulation quality than steel, but it is not suitable for high-rise construction. Also wood is vulnerable to insect damage and rot.
Continuous Insulation: Insulation that covers the framing members and thereby provides a greater insulation value. This is especially important for metal framing to control condensation.
Structural Insulated Panels (SIPs): are rigid panels of foam insulation joined to oriented strand board (OSB). Typically used as floors, walls, and roofs on smaller buildings.
Insulated Concrete Forms (ICFs): are forms/molds or hollow blocks with built-in insulation. These are stacked and filled with reinforcing bar and concrete.
Both SIPS and ICFs have an insulation value of approximately R5 (U-0.20) per inch. ICFs have thermal mass benefit. Both also reduce infiltration/noise.
Straw Bales: Many factors can affect the insulating quality of a straw bale wall, including moisture content, bale size and bale orientation. Green Building Studio has adopted the California Energy Commission's default assumption insulation value of R-30 (U-0.033) for Straw Bale construction.