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Extendable Window Bars

Protect vulnerable windows with strong, adjustable window bars designed for simple DIY installation.
DIY Xpanda window bars are widely used by homeowners, landlords, property managers and small businesses across New Zealand to strengthen window security and create a visible deterrent against break-ins.
Our extendable window security bars (also known as burglar bars) are designed to fit a wide range of window sizes while remaining easy to install with basic tools.

  • Adjustable sizes to fit many window openings
  • Simple DIY installation with basic tools
  • Strong steel construction for visible deterrence
  • Suitable for homes, rentals and small businesses
  • Nationwide NZ delivery

Window Bars Variations

You can install the window bars either horizontally or vertically.
Each option provides strong physical window protection while allowing flexibility for different installations.
Expandable Window Bars
Extendable Window Bars Size Comparison
Variants Expandable Heights Fixed Widths Spaces Among Bars Bar Diameters Bar Type Price
Type A Min: 485mm
Max: 900mm
340mm 120mm Outer: 16mm
Inner: 12mm
3 round bars $54
Type B (BLACK) Min: 900mm
Max: 1650mm
340mm 120mm Outer: 16mm
Inner: 12mm
3 round bars $81
Type C (BLACK) Min: 630mm
Max: 1100mm
300mm 100mm Outer: 20mm
Inner: 15.88mm
3 square bars $66
Type D Min: 630mm
Max: 1100mm
420mm 100mm Outer: 20mm
Inner: 15.88mm
4 square bars $99
Type E Min: 630mm
Max: 1100mm
540mm 100mm Outer: 20mm
Inner: 15.88mm
5 square bars $108
Expandable Window Bars Installation Example
  • Extendable Window Bars | 3 Square Bars | 630-1100mm Wide x 300mm High (C) - Commercial, Residential, Window Bars, Windows - Black DIY XPANDA
  • Extendable Window Bars | 3 Round Bars | 900-1650mm Wide x 340mm High (B) - Commercial, Residential, Window Bars, Windows - Black DIY XPANDA
  • DIY Xpanda Window Bars
  • Extendable Window Bars | 3 Round Bars | 485-900mm Wide x 340mm High (A) - Commercial, Residential, Window Bars, Windows - Black DIY XPANDA
  • Extendable Window Bars | 5 Square Bars | 630-1100mm Wide x 540mm High (E) - Commercial, Residential, Window Bars, Windows - Black DIY XPANDA
  • Extendable Window Bars | 3 Square Bars | 630-1100mm Wide x 300mm High (C) - Commercial, Residential, Window Bars, Windows - Black DIY XPANDA
  • Extendable Window Bars | 3 Square Bars | 630-1100mm Wide x 300mm High (C) - Commercial, Residential, Window Bars, Windows - Black DIY XPANDA

DIY Xpanda window bars are used in many applications across New Zealand, including:

  • Residential homes
  • Rental properties
  • Apartments
  • Workshops and garages
  • Small business premises

They are often installed alongside alarms, cameras and other security measures to improve overall protection.

Choosing the Right Window Bars

When selecting window bars, measure the inside width and height of your window frame first.
For best strength and rigidity, it is recommended that the bars are not installed fully extended.
If your window width is close to the maximum expansion size, consider choosing the next larger size range.

Example: Window width: 900mm

Better choice: window bars that extend to 1100mm or 1650mm, not exactly 900mm.

Extendable Window Bars 3 Round 900-1650mm (B) - Commercial, Residential, Window Bars, Windows - Black DIY XPANDA

Window Bars Recommendation Tool (Beta)

The tool below recommends suitable window bars for your use. Since this tool is a beta version, please double-check the measurements before making a purchase, and confirm your window/door frame measurements in the customer note section on your cart page.

Please click "Check Options" below to begin.

Important Note: Window bars are more durable when they are NOT fully extended.

Extendable Window Bars

Your Header Menu

Frame Measurement
(Inside Window / Door Frame)




Best Fit Option

Click "Check Options" to view recommended window bar types and quantities for maximum coverage.

Best Value Option

Click "Check Options" to see the best value option with the fewest window bars that would fit into your window.

About Adjustable Security Window Bars - Window Bars NZ

Window Bars for Homes and Businesses

DIY Xpanda extendable window bars provide flexible protection for different window sizes.

These bars can be installed horizontally or vertically depending on your window layout and security needs.

They are commonly used to secure:

  • Ground-floor windows
  • Basement windows
  • Rental properties
  • Workshops and garages
  • Shop windows and small business premises

Window bars help create a visible physical barrier that can deter intruders and delay forced entry.

How to Choose and Install Window Bars

How to install Extendable Window Bars

Step 1: Measure Inside Your Window Frame

First things first, let's measure the inside of your window frame.

Particularly inside the window frame's reveal

DIY-Xpanda-Blog-Window-Frame-Reveal-Necessary process to install Window Security Bars

This step is important because it will help you decide whether to install the bars vertically, horizontally, or even use multiple bars side-by-side. Take your time with this part—no need to rush. Think about which windows or doors you want to secure the most to protect your home.

Expandable Window Security Bars Measurement

Also, to retain rigidity in the middle of the bars, do not exceed the maximum expanded width/height.
So if you have a window size that is 900mm width by 900 mm width, you would not want to choose the window bar that extends to 900 or 905mm, rather choose that extends to something like 1100mm or 1650mm.

<Round or Square Bars>

    One thing to note, if you are choosing square bars, you can install the expanding window security bars on top of the frame / reveal in addition to installing them inside the frame (window sill)

    Round bar and square bar shape explanation for installing DIY Xpanda's window security bars.
    Direction of fixing explanation for installing DIY Xpanda's window security bars.

    Step 2: Gather Your Tools and Materials

    Before we get started, let's make sure we have everything we need.
    Here’s a list of tools and materials:

    • DIY Xpanda expandable window security bars
    • Measuring tape
    • Pencil or marker
    • Drill with the right drill bits
    • Screws and anchors (included in the expandable window security bars)
    • Screwdriver
    • Level
    Images of some of the tools needed for installing DIY Xpanda's window security bars, red and black cordless power drill beside black and red cordless power drill. fixings for installing DIY Xpanda's window security bars.

    Step 3: Mark the Mounting Points

    Using your measurements from Step 1, mark the spots on the window frame where you’ll drill the holes for the mounting brackets. Make sure the marks are level and evenly spaced. Double-checking your marks now will save you from any hassles later on.

    Step 4: Drill the Holes

    Now, it’s time to drill the holes. Be gentle and precise, using the marks as your guide. If you’re drilling into a tougher surface like masonry or concrete, use the appropriate drill bit and anchors. Take it slow and steady.

    Drilling explanation for installing DIY Xpanda's window security bars.

    Step 5: Attach the Mounting Brackets

    Next, attach the mounting brackets to the window frame with the screws and anchors. Make sure they’re nice and tight. The brackets need to be stable to keep the expandable window bars secure.

    Fixing explanation for installing DIY Xpanda's window security bars.

      Step 6: Install the Expandable Window Security Bars

      Expand the window security bars to fit the width of your window frame. Place them into the mounting brackets and make sure they’re aligned properly. Tighten any adjustment screws or bolts to lock the bars in place.

      Installation direction explanation for installing DIY Xpanda's window security bars.

      Here are more detailed breakdowns of how to screw the expandable window security bars:
      https://www.youtube.com/watch?v=JGdsgqaYNW4

      Step 7: Test the Security

      Give the expandable window security bars a gentle push and pull to check their stability. They should be firmly in place without any wobbling. If they feel loose, tighten the brackets or adjustment screws a bit more. 
      Make any last adjustments to ensure everything is just right.
      Check all screws and brackets to make sure they’re tight, and clean up any debris from the installation.

        Window Bars Terminology

        Window bars may also be referred to as:

        • burglar bars
        • window security bars
        • window guards
        • security grilles
        • adjustable window bars

        These terms all refer to physical security bars designed to strengthen window protection.

        Looking for a Different Look?
        We have Clear Guard - Polycarbonate Window Guard!

        Clear-Guard Polycarbonate Security Bars - Clear Guard, Commercial, Doors, Gates, Residential, Window Bars, Windows - A DIY XPANDA

        Clear Guard Polycarbonate Window Protection

        If you prefer a more subtle appearance, consider Clear-Guard polycarbonate window protection.
        Clear Guard provides strong impact resistance while maintaining visibility and natural light.
        Choose based on your preference:

        • Clear Guard
          Minimal visual impact with modern transparent panels.
        • Window Bars
          Visible deterrent and strong steel protection.

        Both options help strengthen window security depending on your priorities.

        Check Out Clear Guard

        Looking for a high quality Window Mesh?

        • Magnetic-Insect-Screen-Stay-safe-home-plus
        • Our DIY products are designed to protect against human intrusions.
          BUT if you're looking for a preventative measure against insects and bugs, window screens can help!
          Check out our partner Stay Safe Home Plus and their magnetic insect screens!
          They offer custom-made magnetic window screens that fit your windows perfectly and are built to last.

          Check It Out 

        Customer Reviews

        Customers across New Zealand have installed DIY Xpanda window bars in homes, rentals, and small businesses. Many reviews highlight:

        • Easy installation
        • Fast delivery
        • Strong construction
        • Good value security upgrade

        Click here to provide a review on Google.

        Contact Xpanda Security for Custom Made designs. Please share your security concern along with a photo and the measurements (height and width) of the area you are looking to secure, if possible.

        CUSTOM ORDER?

        If you're having trouble finding what you're looking for, our business affiliate Xpanda Security may be able to help!

        Xpanda Security specializes in creating custom-made and professional physical security products and offers a free security assessment with industry-leading insights.

        ENQUIRE