Black extendable steel window bars installed on a residential window for security protection

Extendable Window Bars NZ

Adjustable DIY Security Window Bars

Extendable DIY Security Window Bars

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

  • Extendable design fits many NZ window sizes
  • Straightforward DIY installation
  • Strong steel construction
  • Fast NZ-wide delivery
  • From $54 (Updated 2026 pricing)

Choose Your Window Bars
Select based on your window width and required coverage.

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

Why Choose DIY Xpanda Window Bars

  • Trusted Across NZ Homes
  • Fast NZ Delivery
  • DIY Installation Using Basic Tools
  • Strong Steel Construction

Find The Right Extendable Window Bars

Measure your window frame and compare recommended options.

Extendable Window Bars

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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.
Expandable Window Bars
Extendable Window Bars Size Comparison
Variants Expandable Heights Fixed Widths Spaces Among Bars Bar Diameters Bar Type Price Suitable For
Type A Min: 485mm
Max: 900mm		 340mm 120mm Outer: 16mm
Inner: 12mm		 3 round bars $54 Best suited for smaller windows (485–900mm)
Type B (BLACK) Min: 900mm
Max: 1650mm		 340mm 120mm Outer: 16mm
Inner: 12mm		 3 round bars $81 Best suited for smaller windows (900–1650mm)
Type C (BLACK) Min: 630mm
Max: 1100mm		 300mm 100mm Outer: 20mm
Inner: 15.88mm		 3 square bars $66 Compact square bars for standard windows
Type D Min: 630mm
Max: 1100mm		 420mm 100mm Outer: 20mm
Inner: 15.88mm		 4 square bars $99 Greater coverage and protection
Type E Min: 630mm
Max: 1100mm		 540mm 100mm Outer: 20mm
Inner: 15.88mm		 5 square bars $108 Maximum coverage within the range
Expandable Window Bars Installation Example

Why Extendable Window Bars?

Extendable window bars allow one product range to fit different window sizes. Main benefits are:

  • Flexible sizing
  • Easier product selection
  • Straightforward installation
  • Practical protection for homes and rentals
  • Extendable design fits a wide range of NZ window sizes

Window Security for Different Areas of Your Home

Extendable window bars can protect vulnerable ground-floor, basement, bathroom, laundry and garage windows. Depending on your window design, they can add a visible physical barrier while allowing ventilation and natural airflow.

Also known as adjustable window security bars, burglar bars, window guards or window grilles, our ready-made steel bars come in sizes covering window widths from 485mm to 1650mm.

Common applications include:

  • Ground-floor and street-facing windows
  • Basement windows
  • Bathroom and laundry windows
  • Garage and sleepout windows
  • Apartments, townhouses and duplexes
  • Infill housing and new residential developments
  • Social housing and privately owned homes
  • Body corporate-managed apartment properties
  • Rental properties, subject to owner approval

For rental, apartment, Kāinga Ora or body corporate properties, obtain the required approval before drilling or modifying the window frame.

Window bars are a security deterrent. They are not a child fall-prevention device and cannot guarantee prevention of entry.