What Is a Good STC Rating for Windows? Start at 45
Do traffic, sirens, or late-night noise still reach you through closed windows? The reason is usually the STC (Sound Transmission Class) rating, which measures how well a window blocks airborne sound. The higher the number, the quieter your room. Here is how the ratings compare: Single-pane windows: STC 26-28 Standard double-pane windows: STC 26-32 A good STC rating for windows: 45 or higher Most standard windows are built to hold heat in, not to block noise. A better fix is a secondary window. Soundproof USA installs CitiQuiet soundproof windows inside your existing frame. Laminated glass and a 2-4 inch air gap reach STC 48-54, with no demolition and no change to your home's exterior. They work well for homes, condos, and offices near busy roads, trains, or airports. Get a free quote at SoundproofUSA.