How to Measure Glass for a Window

Tools and Materials:

Measuring Tape

Pencil or Marker

Straight edge or ruler

Instructions:

Determine How You Want to Instal the Glass:

The first step is to decide how you want the glass installed in the window. Three main methods are:

Channel Balances: These balances slide the window, usually a single-hung or double-hung window, up or down.

Ropes: This is a popular choice for heavier windows and is similar to a channel balance.

Pulleys: This method is more common in older homes. It typically involves a rope and pulley and is often combined with a channel balance.

Choose a Type of Glass:

After selecting the installation method, you can choose the glass. Multiple glass types are available, each with pros and cons. Here are a few common options:

Standard glass (float glass): This inexpensive glass type is typically used in windows that don’t require high thermal insulation or UV protection.

Tempered glass: A heat treatment produces this type of glass, which makes it incredibly durable and resistant to breakage.

Laminated glass: Made by bonding two glass layers with a thin layer of plastic, this glass is also tough and secure.

Measure the Window Opening:

With your chosen installation method and glass in mind, you can start measuring for your new glass. Start by removing any existing glass (with safety precautions) and measuring the window opening. Take multiple measurements to ensure accuracy, especially if the opening looks uneven. The glass you order should be slightly smaller than the opening to allow for the necessary space between the glass and the frame. Usually, around 1/16 inch of clearance is enough. Here’s a simple formula you can use:

For single-hung or double-hung windows, subtract 3/8 inch from the width and height measurements of the opening.

For larger or oversized windows, deduct 3/4 inch from the width and height measurements.

Order Custom Glass:

With your measurements in hand, you can now place an order for custom glass. It’s important to give your glazier or glass shop the exact dimensions and specify any special requirements, like the glass type, thickness, or edgework. They will cut the glass to size and finish it accordingly, ensuring it fits your window perfectly.