Learn the Lingo: Window Balance - Ply Gem

Learn the Lingo: Window Balance

In this installment of our Learn the Lingo blog series, we’ll dive into window balances—what they are, the different styles, and how they work.

First things first, what’s a window balance? A window balance is a somewhat hidden window component sitting inside the window frame. It’s only found in double hung or single windows and assists you with the weight of the sash as you open and close your windows. They also hold the top sash of double hung windows closed while they’re not in use.

There are several different types of window balances. Let’s take a look a few of the different types that might be in your window.

Four different types of window balances.

Block & Tackle Window Balance


Currently one of the most popular choices, block and tackle window balance systems include a combination of two or more pulleys, a cord and a spring. The pulleys are grouped as the “block” to reduce the load the homeowner feels. In addition, as the cord (or “tackle”) is pulled by the movement of the sash it stretches or compresses the springs, which are weighted to match the sash weight. The pulleys and springs assist with opening and closing the window.

Coil Window Balance


Coil balances, sometimes referred to as constant force balances, are made of coiled pieces of metal. These balance springs are uncoiled when the sash is closed and recoil to provide the tension to balance the sash weight, allowing for ease of opening and closing of the window.

Weight & Pulley Window Balance

Commonly found in older homes, weight and pulley balances operate by using a counterweight to hold the sash in place, preventing it from slamming closed when you open the sash and let go. The weight, usually made of metal, is half the weight of the sash it is supporting. The weights are used in pairs suspended on a cord or chain in the right and left balance tracks. The cord or chain passes through a pulley near the top of the window frame before attaching to the sash.

Spiral Window Balance

To aid in opening windows, as well as hold windows open and closed, spiral balances utilize a spiral-shaped rod within a tube. This rod connects to a spring, which is what provides the tension for supporting the sash. The tension is adjusted by being wound to match the sash it is supporting.

So what’s the main point here? No matter the type of balance, it’s job is make opening and closing your window easier on you.