Gas strut windows are a popular choice for homeowners, architects, and commercial designers looking to create a seamless connection between indoor and outdoor spaces. Whether installed above an outdoor kitchen, home bar, café counter, or entertainment area, these windows provide unobstructed views, improved ventilation, and convenient access for serving.
However, even the highest-quality gas strut window will only perform as intended if it’s manufactured to the correct dimensions. Accurate measurements are essential for ensuring smooth operation, proper sealing, structural integrity, and long-term durability.
This guide explains how to measure for gas strut windows, whether you’re purchasing a standard-size model or a custom-made unit.
Why Accurate Measurements Matter
Unlike conventional windows, gas strut windows open outward and upward using gas-assisted struts. Because the sash projects away from the building, precise measurements are essential to ensure adequate clearance, safe operation, and proper installation.
Correct measurements help you:
- Ensure a precise fit within the structural opening
- Achieve smooth opening and closing
- Maintain weather resistance and energy efficiency
- Avoid costly manufacturing errors
- Reduce installation time
- Ensure sufficient clearance for the open sash
- Maximize safety and functionality
Taking accurate measurements before ordering can prevent delays and ensure your new gas strut window performs as expected from day one.
Tools You’ll Need
Before measuring your opening, gather the following tools:
- Steel tape measure
- Spirit level
- Pencil
- Notepad or mobile device for recording dimensions
- Step ladder (for higher openings)
- Measuring assistant for larger windows
For the most accurate results, always measure in the same unit, either millimetres or inches.
Measure the Width
Begin by measuring the width of the structural opening.
Take three separate measurements:
- Top
- Middle
- Bottom
Record each measurement carefully.
If there is any variation, use the smallest width when ordering your gas strut window. This ensures the frame can be installed correctly without requiring modifications to the opening.
Measure the Height
Next, measure the height from the finished sill or countertop level to the top of the structural opening.
Take measurements at:
- Left side
- Centre
- Right side
If the measurements differ, use the smallest height.
This helps compensate for any irregularities in the opening and ensures proper frame alignment.
Measure the Structural Opening
When replacing an existing window, avoid measuring the old frame.
Instead, measure the structural opening after removing any trims or finishes where possible.
This provides a more accurate representation of the available installation space and helps ensure the new window is manufactured correctly.
Check That the Opening Is Square
Gas strut windows rely on accurate frame alignment for smooth operation.
Measure diagonally from corner to corner:
- Top left to bottom right
- Top right to bottom left
The two measurements should be nearly identical.
Significant differences may indicate that the opening requires adjustment before installation.
Check That the Sill Is Level
The sill provides the foundation for the window.
Use a spirit level to ensure it is perfectly horizontal.
An uneven sill may result in:
- Poor sash alignment
- Uneven gaps
- Difficult operation
- Reduced weather performance
Correcting an uneven sill before installation helps prevent future problems.
Allow Clearance for the Opening Sash
One of the defining features of a gas strut window is its outward-opening sash.
Before selecting your window size, make sure there is adequate external clearance.
Consider nearby:
- Pergolas
- Roof overhangs
- Balconies
- Outdoor lighting
- Ceiling fans
- Trees and landscaping
- Awnings
Ensuring sufficient clearance allows the sash to open fully and safely.
Standard Gas Strut Window Sizes
Gas strut windows are available in a wide range of standard dimensions suitable for residential and commercial applications.
Common sizes include:
- 36 × 24 inches
- 48 × 36 inches
- 60 × 36 inches
- 72 × 36 inches
- 96 × 36 inches
- 120 × 36 inches
Larger custom configurations are also available for serving counters, outdoor kitchens, bars, restaurants, cafés, and entertainment spaces.
If your project requires non-standard dimensions, custom gas strut windows can be manufactured to suit your exact opening.
Measuring for Custom Gas Strut Windows
Custom windows require more than just width and height.
Before ordering, you should also confirm:
- Structural opening dimensions
- Frame depth
- Wall construction
- Finished countertop height
- External clearance
- Opening direction
- Glazing preferences
- Handle position
- Interior and exterior finishes
Providing complete project information helps ensure your custom window is manufactured accurately.
Measuring for Outdoor Kitchens and Serving Windows
Gas strut windows are commonly installed above outdoor kitchen counters and entertainment bars.
When measuring these applications, consider:
- Countertop thickness
- Splash back height
- Cabinet clearances
- Appliance locations
- Serving space
- Exterior traffic flow
- Customer access (commercial projects)
Proper planning ensures the open sash doesn’t interfere with normal use of the space.
Replacement vs New Construction
Replacing an Existing Window
If you’re replacing an existing serving window or kitchen window:
- Measure the structural opening.
- Inspect surrounding framing.
- Check for moisture damage.
- Confirm sill level.
- Verify lintel condition.
Do not rely solely on the dimensions of the old window.
New Construction
For new builds:
- Measure only after framing is complete.
- Confirm final countertop height.
- Verify finished floor levels.
- Ensure structural supports are installed.
- Compare actual dimensions with architectural plans.
This helps eliminate discrepancies before manufacturing begins.
Common Measurement Mistakes to Avoid
Many ordering errors can be prevented by avoiding these common mistakes:
- Measuring only once
- Measuring the existing frame instead of the opening
- Ignoring external clearance requirements
- Forgetting countertop height
- Not checking whether the opening is square
- Using inconsistent units
- Assuming all openings are level
- Ordering before confirming final site dimensions
Double-checking every measurement helps avoid costly delays and ensures a smooth installation.
Measurement Checklist
Before placing your order, confirm that you have:
- ✔ Measured the width in three locations
- ✔ Measured the height in three locations
- ✔ Checked the opening is square
- ✔ Confirmed the sill is level
- ✔ Measured the structural opening
- ✔ Verified countertop height (if applicable)
- ✔ Allowed clearance for the opening sash
- ✔ Confirmed standard or custom sizing requirements
When Should You Request a Professional Site Measure?
While preliminary measurements can be taken by homeowners or builders, professional site measurements are recommended for:
- Large windows
- Custom-sized units
- Commercial installations
- Outdoor kitchens
- Pass-through serving windows
- Renovation projects with irregular openings
Professional measuring helps reduce manufacturing errors and ensures your gas strut window is built to the exact specifications of your project.
Frequently Asked Questions
Can I measure a gas strut window myself?
Yes. Homeowners can take initial measurements using a tape measure and spirit level. However, professional verification is recommended before ordering a custom unit.
Should I measure the existing frame?
No. Measure the structural opening whenever possible, as existing frames may conceal variations that affect the fit of the new window.
What if my opening isn’t perfectly square?
Minor variations are common, but significant differences should be corrected before installation to ensure smooth operation and proper sealing.
Are custom gas strut windows available?
Yes. Custom gas strut windows can be manufactured in a wide range of sizes, glazing options, and configurations to suit residential and commercial projects.
Why is external clearance important?
Because the sash opens outward and upward, sufficient space is needed to prevent interference with roofs, pergolas, lighting, landscaping, or other nearby structures.
Accurate measurements are the foundation of a successful gas strut window installation. Taking the time to measure the width, height, structural opening, sill level, and external clearance carefully will help ensure your new window fits perfectly, operates smoothly, and delivers years of reliable performance.
Whether you’re creating a modern outdoor kitchen, a stylish server, or a commercial pass-through window, following this measurement guide will help you order with confidence and achieve the best possible installation results.
