Definition
A measure of thermal resistance — how well a material resists heat flow. Higher R-value means better insulation. Standard siding has minimal R-value; insulated siding adds R-2 to R-5. For windows, R-value is the inverse of U-factor (e.g., U-factor 0.25 = R-value 4.0).
Related Terms
Aluminum Siding
Lightweight metal siding popular from the 1940s-1970s. Durable and low-maintenance but dents easily and can oxidize over time. Still found on many Colorado homes.
Argon Gas
An odorless, colorless gas used to fill the space between panes in insulated glass units. Argon is denser than air and reduces heat transfer, improving the window's insulating ability by 30-40%.
Awning Window
A window hinged at the top that opens outward from the bottom. Provides ventilation even during light rain because the open sash acts as an awning.
Back-Primed
Siding that has been primed (sealed) on the back side before installation. Back-priming prevents moisture absorption from behind, extending the life of the siding — especially important for wood and fiber cement.
Batten
A narrow vertical strip applied over joints between siding panels in a board-and-batten installation. Creates a distinctive vertical pattern.
Bay Window
A window that projects outward from the exterior wall, typically with a large center window flanked by two angled side windows. Creates a wider interior shelf and more natural light.
Board and Batten
A siding style using wide vertical boards with narrow battens covering the seams. Popular for farmhouse, modern, and rustic architectural styles.
Bow Window
Similar to a bay window but with four or more windows arranged in a gentle curve rather than angled segments.
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