NFRC Label

Related terms

• Air Leakage (AL)

  The rate of air infiltration through a window assembly; lower is tighter and more efficient.

• SHGC (Solar Heat Gain Coefficient)

  The fraction of solar heat a window admits (0–1); lower reduces cooling load. Climate determines whether high or low SHGC is desirable.

• U-Factor

  The rate of non-solar heat flow through a window; lower means better insulation. The primary winter-performance metric on the NFRC label.

• Obscure / Privacy Glass

  Textured, frosted, or patterned glass that transmits light but blocks view, used in bathrooms and entry sidelights.

• New-Construction Window

  A window with a nailing flange for installation before siding goes on, used in new builds and full-frame replacements with siding removed.

• Panel Door

  A door built of a stile-and-rail frame surrounding raised or flat panels — the traditional look (e.g., two-panel, six-panel).

• Nailing Flange / Fin

  An integral perimeter fin on new-construction windows fastened to the sheathing and integrated with flashing for a weather-tight install.

• Picture Window

  A large fixed (non-opening) window that maximizes view and light. Most energy-efficient type because there is no operating gap to leak air.