Extendable Window Bars NZ

Easy DIY installation • Strong steel construction • Fast NZ delivery

White-round-Window-Bars-Installed

Adjustable Steel Window Security for NZ Homes

Protect vulnerable windows with adjustable steel window bars designed for straightforward DIY installation.

Each bar combines a fixed section with an extendable section, allowing the overall width to be adjusted to suit different window openings.

Install horizontally or vertically depending on your window layout.

Round bars are spaced 120mm apart, while square bars are spaced 100mm apart. This spacing maintains airflow and visibility while allowing the fixed side to cover beyond its physical width. For example, Type A has a 340mm fixed width but can effectively cover a wider area when installed with the recommended spacing.

Get Extra Coverage from the Fixed Side

The bars are designed with a set gap between each parallel bar:

  • Round bars are spaced 120mm apart
  • Square bars are spaced 100mm apart.

This spacing maintains airflow and visibility while allowing the fixed side to cover beyond its physical width.
For example, Type A has a 340mm fixed width but can effectively cover a wider area when installed with the recommended spacing.

Expandable Window Bars
Extendable Window Bars Size Comparison
Variants Expandable Side Fixed Side Bars Spaces Bar Type Price
Type A Min: 485mm
Max: 900mm		 340mm 120mm 3 round bars $54
Type B (BLACK) Min: 900mm
Max: 1650mm		 340mm 120mm 3 round bars $81
Type C (BLACK) Min: 630mm
Max: 1100mm		 300mm 100mm 3 square bars $66
Type D Min: 630mm
Max: 1100mm		 420mm 100mm 4 square bars $99
Type E Min: 630mm
Max: 1100mm		 540mm 100mm 5 square bars $108
Expandable Window Bars Installation Example
Left Image
Right Image

Not Sure Which Size to Choose?

Measure your window width and height.
Choose a security bar that extends beyond your window opening rather than matching the exact size.

Example:
Window width = 900mm
Recommended range:
1100mm or 1650mm

More overlap can help improve stability and coverage.

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

Installed in NZ Homes

Commonly used on ground-floor windows, rental properties, garages, storage areas and other accessible windows.

  • Extendable window bars with 3 round steel security bars for residential window protection
  • DIY Xpanda Window Bars
  • Black extendable steel window bars installed on a residential window for security protection
  • Extendable window bars with 5 square steel security bars for residential window protection
1 6

Why Choose Window Bars?

  • Adjustable sizing
  • Strong steel construction
  • DIY installation
  • Maintains airflow and visibility
  • Ready to ship NZ-wide

Simple Installation

How to Install Expandable Window Security Bars


Install Your Window Bars in 7 Simple Steps

DIY Xpanda's expandable window security bars are designed for straightforward DIY installation.

They can be installed horizontally or vertically, and multiple bars can be installed in parallel to suit different window layouts.

Typical installation time is approximately 30 minutes to 1 hour, depending on the window and fixing surface.

Installation Overview
  1. Measure your window
  2. Gather your tools
  3. Mark the mounting points
  4. Drill the holes
  5. Attach the mounting brackets
  6. Install the window bars
  7. Check the installation

Step 1: Measure Your Window

Measure the inside of the window frame, particularly the window reveal.

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

Accurate measurements will help you choose the correct window bar size and decide how the bars should be positioned.

You can install the bars:

  • Horizontally
  • Vertically
  • In parallel with multiple bars

Each window bar has a fixed section and an extendable section, allowing its overall length to be adjusted to suit the opening.


Extendable Window Bars Extension Horizontally or vertically

Do Not Extend to the Maximum if You Can Avoid It

To help retain rigidity through the centre of the bars, avoid choosing a size that needs to be extended to its absolute maximum.

For example, for an opening around 900mm wide, choose a bar with additional extension available rather than one with a maximum extension of only 900–905mm.


Get Extra Coverage from the Fixed Side
The bars have a set spacing between each parallel bar:
  • Round bars: 120mm spacing
  • Square bars: 100mm spacing

This spacing helps maintain airflow and visibility while providing practical window security. It also means the fixed section can cover beyond its physical width when planning multiple-bar installations. For example, Type A has a fixed width of 340mm, but the overall effective coverage can be wider when the recommended spacing between bars is taken into account.

Round bars are spaced 120mm apart, while square bars are spaced 100mm apart. This spacing maintains airflow and visibility while allowing the fixed side to cover beyond its physical width. For example, Type A has a 340mm fixed width but can effectively cover a wider area when installed with the recommended spacing.

Round Bars or Square Bars?

Both styles are extendable, but the fixing options differ.

Round bar and square bar shape explanation for installing DIY Xpanda's window security bars.
Round Bars
Designed primarily for installation inside the window reveal.

Square Bars
Square bars can be installed:
  • Inside the window reveal (sill fix)
  • Onto the face of the frame or surrounding surface (face fix)
Choose the fixing method that best suits your window and installation surface.

 

Face fix of window bars Sill fix window bars

Step 2: Gather Your Tools


Before installation, prepare the tools and materials you need.Recommended Tools
  • DIY Xpanda expandable window security bars
  • Measuring tape
  • Pencil or marker
  • Drill
  • Appropriate drill bits
  • Screws and anchors
  • Screwdriver
  • Level
Make sure the drill bits and fixings are appropriate for the material you are drilling into.

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


Position the mounting brackets and mark where the fixing holes will be drilled.Make sure the mounting points are:
  • Level
  • Evenly positioned
  • Properly aligned
Check your measurements again before drilling.


Step 4: Drill the Holes

Drill the fixing holes using the marks as your guide.
Use the appropriate drill bit for the installation surface. For harder materials such as masonry or concrete, use suitable drill bits and anchors.

 

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


Step 5: Attach the Mounting Brackets

Secure the mounting brackets to the window frame using the appropriate screws and anchors. Make sure each bracket is firmly fixed before installing the bars.

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

Step 6: Install the Window Bars

Extend the security bars to fit the opening. Place the bars into the mounting brackets and check that they are properly aligned. Do not extend the bars beyond their recommended maximum size.

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

Step 7: Check the Installation

Once installed, gently push and pull the bars to check their stability.
Make sure:
  • The bars are firmly secured
  • There is no excessive movement
  • All brackets are tight
  • All screws are secure
  • The bars are correctly aligned
Make any final adjustments before finishing the installation.

How to install window guard: In this case, we installed window bars in parallel vertically.

Installation Instructions

A written installation guide is also available: Download the Expandable Window Bars Installation Instructions. You can also watch the installation demonstration.

 

Need Help?

If you are unsure which size, fixing method or installation direction is right for your window, please contact DIY Xpanda before ordering or installing.
Correct measuring and planning will make installation easier and help you choose the right window security bars for your home.

Need a Custom Size?

If your window is larger than the available DIY Xpanda expandable window bars, a custom-made solution may be more suitable. For custom-designed, manufactured and installed window security bars, visit Xpanda Security.

 

What Are Window Bars?

Also known as adjustable window bars, extendable window bars, burglar bars, window security bars and window guards.

Window bars create a physical barrier across an opening and can be used alongside locks, lighting, alarms and CCTV as part of layered home security.

Layered Security

Often paired with alarms and cameras for layered security.
Window security is often one part of a broader home protection approach.

Start With the Window That Concerns You

You don't need to change every window at once.

If one accessible window is making you uncomfortable, start there. Measure the opening, choose a suitable option and make one practical improvement at a time.

Not sure what fits? Send us a photo and your measurements and we'll help you look at the options.

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

Prefer a Less Visible Option?

Clear Guard (Polycarbonate)

A more discreet alternative to traditional steel bars, helping maintain visibility and natural light while adding physical window protection.

  • Transparent appearance
  • Impact resistant
  • Maintains visibility
  • Preserves natural light
Check Out Clear Guard