How to Measure for Casement Windows?


Accurate measurements are the cornerstone of successful casement window replacement or installation. Getting it right ensures a snug fit, enhancing energy efficiency and aesthetics. In this guide, we’ll explain the measuring process for casement windows, breaking it down into simple steps. 

Precision in measurement guarantees a seamless integration, preventing drafts and leaks that can compromise your home’s comfort. So, grab your tape measure, whether upgrading or installing anew. Let’s dive into the fundamentals of measuring for casement windows and ensure your home enjoys the perfect fit.

Steps of measuring Casement Windows

Here is the step-by-step guide to measuring casement windows to ensure a flawless fit for your Chesterfield home.

1. Removing Interior Trim

To simplify the task, take off the inner trim encircling the window. Cut through any paint, sealing the trim to the wall. Slide the tip of a flat-head screwdriver or a comparable prying tool behind the wooden trim, getting it in as far as possible. Tap the tool and pry the trim away from the wall and window opening. Continue this process around the window, removing the trim similarly. This will unveil the entirety of the window framing and the window edge, making your job more manageable.

2. Clearing Obstructions and Disassembling Components

Open the window and remove the crank if it’s there. If there’s a window screen, remove that too. Make sure to clear any other items in the window’s way, like plants, sun catchers, or curtains. This ensures smooth and unobstructed access to the window, making the overall process easier. By completing these simple steps, you’ll be ready to proceed with the task at hand, whether it’s cleaning, repairing, or any other window-related activity.

3. Measuring Window Width

Use a steel tape measure to go from one side of the window’s jamb to the opposite inner side. Measure at the top, bottom, and approximately halfway up the window for accuracy. Ensure you use a steel tape measure for precision. Select the smallest one from these measurements and mark it as the width. This straightforward process guarantees an accurate width measurement, crucial for further tasks like fitting or replacing the window components.

4. Measuring Window Height

Measure the window’s height by using a tape measure from the bottom of the window sill to the inner top edge, known as the head jamb. Ensure measurements are taken on both sides and approximately halfway across the width for accuracy. Label the smallest measurement as the height. This straightforward process provides a reliable height measurement, crucial for various tasks such as selecting appropriate window treatments or determining sizing for replacement components.

5. Assessing Wall Thickness and Glass Dimensions

Determine the depth of the window opening by gauging the thickness of the wall, similar to how you’d measure along a door opening. Typically, for 2-by-4 stud wall construction, the width is around 4.5 inches, and for 2-by-6 stud wall construction, it’s about 6.5 inches. Alternatively, measure from the opening’s edge to the glass on both sides of the window. Add the glass thickness to confirm the wall depth. This uncomplicated process helps ensure accurate measurements, which is essential for tasks like fitting or installing window components in line with the wall structure.

Pro tips: Typically, the height and width are trimmed by ¼ inch to ensure space to position and adjust the window inside the opening.

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The Recap

Precision is key in wrapping up our guide on measuring for casement windows. Take accurate measurements, ensuring width, height, and depth are accounted for. A sturdy foundation for window installation begins with meticulous sizing. Double-check your figures before making any purchases, as even the smallest error can lead to a mismatch. 

Remember, a snug fit enhances energy efficiency and overall functionality. So, invest time in this foundational step, and you’ll be rewarded with windows that seamlessly integrate into your space. For maximum precision, take that extra step and contact a window installer. Their expertise ensures accurate measurements, guaranteeing a seamless fit for your new casement windows.

Director at Chesterfield Window Centre | Website | + posts

In 2005, I founded Chesterfield Window Centre with a vision to redefine the window and door industry through a commitment to quality, innovation, and customer satisfaction. The journey began with a deep understanding of the market, identifying gaps, and envisioning a business that not only meets but exceeds customer expectations.

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