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 trap heat that is generated by lights, people, and other internal loads, within the building. It reduces 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, and therefore can control condensation and moisture better 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.
Cool Roof: Typical rolled roofs, built-up roofs, and composition roofs absorb between 70-90% of incident solar radiation. Cool Roofs absorb 25-40% of incident radiation (aged performance). Asphalt shingles are cheap and prevalent and all roofers know how to install them. But, they are a very poor choice for reflecting incoming solar radiation. The solar reflectance of all commercial asphalt shingles is low (premium white shingles are only about 30% reflective, and other colors reflect less.)
In addition to reducing the heat gain within a building, cool roofs may also benefit the immediate surroundings by reducing the heat island effect—the result of many dark surfaces within an urban environment that can actually increase the ambient air temperatures by a few degrees.
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.