How to Install Shutters on Out-of-Square Windows? | DIY EASYFIT SHUTTERS

Not all windows are perfectly square — especially in older Australian homes, coastal properties, or renovated houses. If your measurements don’t quite line up, don’t worry. Installing DIY plantation shutters on out-of-square windows is completely achievable with the right approach.

In this guide, we’ll explain what out-of-square windows are, why they happen, and how to install shutters so they still look clean, professional, and operate smoothly.

What Is an Out-of-Square Window?

A window is considered out of square when the measurements differ from top to bottom or side to side. This means:

One corner sits higher or lower than the others
The sides aren’t perfectly vertical
The top and bottom aren’t perfectly level

This is very common in:

Older homes
Timber-framed houses
Renovations or extensions
Coastal properties affected by movement and humidity

Why Accurate Measuring Matters

When installing DIY plantation shutters, accurate measuring is essential — especially for out-of-square windows.

If a window isn’t square and measurements aren’t handled correctly, you may experience:

Visible gaps
Panels that rub or don’t close properly
Frames that look uneven

The good news? Plantation shutters are very forgiving when installed correctly.

Step 1: Measure in Multiple Places

Never rely on a single measurement.

For each window, measure:

Width at the top, middle, and bottom
Height on the left, centre, and right

👉 Always use the smallest measurement when ordering shutters. This ensures the shutters fit without forcing them into the opening.

Step 2: Choose the Right Mounting Option

Recess Mount (Inside the Window)

Best for minimal out-of-square windows
Requires enough depth and fairly even walls
Allows frames to hide slight imperfections

Face Mount (Outside the Window)

Ideal for heavily out-of-square windows
Covers uneven edges and plaster lines
Creates a clean, symmetrical look

If your window is noticeably uneven, a face fit is often the best solution.

Step 3: Use Packing or Shims to Level the Frame

Packing pieces (also called shims) are your best friend.

During installation:

Place shims behind the frame where needed
Level the frame vertically and horizontally
Secure the frame only once it sits perfectly square

This step allows your shutter frame to remain square even if the wall or window opening isn’t.

Step 4: Check for Even Gaps Before Securing

Before fully fixing the frame:

Dry fit the frame
Check for even gaps around all sides
Open and close the panels to ensure smooth operation

Minor adjustments at this stage can make a big difference in the final result.

Step 5: Install Panels and Fine-Tune

Once the frame is secure:

Hang the panels
Adjust hinges if needed
Test louvre movement and panel swing

DIY plantation shutters allow for small adjustments that help accommodate irregular openings.

Step 6: Hide Imperfections with the Right Frame Choice

Choosing the right frame style can visually correct uneven windows.

Frames help:

Conceal uneven plaster
Hide gaps caused by out-of-square openings
Create straight visual lines

This is why framed shutters are often recommended for older homes.

Pro Tips for Out-of-Square Windows

✔ Always measure twice
✔ Never force a frame into place
✔ Use a spirit level at every stage
✔ Don’t skip the dry fit
✔ When in doubt, face mount

DIY doesn’t mean guessing — it means installing smart.

Why DIY EasyFit Shutters Work Well for Uneven Windows

DIY EasyFit Shutters are designed to handle real-world homes, not just perfect new builds.

Our shutters feature:

Aluminium-reinforced stiles and blades for stability
VOC-free, water-based paint
Easy-to-install frames
25-year warranty (terms & conditions apply)

They’re ideal for Queensland and NSW homes where movement and settling are common.

Ready to Order Your DIY Shutters?

If your windows aren’t perfect — that’s okay. With the right measuring and installation approach, your shutters will still look flawless.

👉 Get your free quote here:
https://diyeasyfitshutters.com.au/quote/

👉 Or order a free sample box:
https://diyeasyfitshutters.com.au/request-a-sample/

🔗 Related Blogs

How to Measure for DIY Plantation Shutters
https://diyeasyfitshutters.com.au/all-about-shutters/how-to-measure-for-diy-plantation-shutters/

The Frame Game: Choosing the Right Shutter Frame
https://diyeasyfitshutters.com.au/all-about-shutters/the-frame-game/

How to Install Your DIY Plantation Shutters
https://diyeasyfitshutters.com.au/all-about-shutters/how-to-install-your-diy-plantation-shutters/

Are Plantation Shutters Worth the Cost? Myth vs Reality
https://diyeasyfitshutters.com.au/all-about-shutters/are-plantation-shutters-worth-the-cost-myth-vs-reality/