Guide · · 5 min read
Cat door or dog door in an aluminium door: the NZ guide
Most NZ homes have aluminium doors, and yes, they can take a pet door. The trick is that it goes in the glass, not the aluminium. Here is how it works for hinged doors, ranch sliders and bi-folds.
By the Pet-Tek International team, Auckland — designers of Catwalk® and Dogwalk® since 1999.
Walk down almost any street in New Zealand and the back doors are aluminium: a hinged door to the deck, a ranch slider to the lawn, or a run of bi-folds. People often assume that rules out a cat door or dog door. It does not. An aluminium door is really a frame holding a sheet of glass, and the glass is exactly where a Catwalk® or Dogwalk® door is designed to go.
The rule: in the glass, never the frame
Aluminium joinery frames are hollow extrusions. They hold the glass, carry the hinges, rollers and locks, and keep the weather out. Cutting a hole through one weakens it, so the frame is never cut. Instead, the pet door goes through the glass:
- A glazier cuts a round hole in the glass, or makes a new pane with the hole in it.
- The two halves of the pet door frame clamp through the hole from each side.
- Nothing is screwed into the glass, and the aluminium is never touched.
The round cut-out is what makes this work: a circle is the strongest shape to cut in glass, and every door in the range uses one. Sizes run from 245 mm for the Catwalk® Standard to 385 mm for the Dogwalk® Medium.
Single or double glazing?
Look at the edge of the glass, or the stamp in a corner. Most aluminium doors fitted in the last couple of decades are double glazed: two panes with a sealed gap between them.
- Single glazing can usually be cut in place by a glazier, unless it is toughened.
- Double glazing or toughened glass cannot be cut once it is made. The glazier measures your pane, orders an identical unit with the hole made at the factory, and swaps it in. Our double glazing guide explains the process step by step.
Then choose a door whose glass range covers your pane. The Dual Glaze models take the thick units: the Catwalk® Maxi Dual Glaze fits glass from 3 to 28 mm, the Dogwalk® Intermediate from 4 to 32 mm and the Dogwalk® Medium from 3 to 32 mm. The Catwalk® Multi-Magnetic fits 3 to 26 mm and only opens for your own cat.
Which aluminium door do you have?
Hinged aluminium door
The simplest case. The pet door goes low in the glass panel, above the bottom rail of the frame, at your pet’s belly height. Any door in the glass range works; pick it by your pet’s size and your glass thickness.
Aluminium ranch slider
A slider has one extra problem: the moving panel slides behind the fixed one, so a pet door that sticks out too far would catch. That is what the Slim Line models are for. The Catwalk® Maxi Slim Line stands just 9 mm proud of the glass, and the Dogwalk® Intermediate Slim Line and Medium Slim Line are just as low, so the slider still opens all the way and still locks. See our guides to a cat door for a ranch slider and a dog door for a sliding glass door.
Aluminium bi-fold doors
Bi-fold panels fold flat against each other, so treat them like a slider: use a Slim Line model, and put it in a panel where the folded stack will not press on the flap. Your glazier will check the clearance when they measure.
Doors with a solid lower panel
Some aluminium doors have a solid infill panel at the bottom instead of glass. If that panel is flat and 5 to 36 mm thick, a wood-fitting door can go into it, as long as the whole cut-out stays inside the panel and clear of the frame. The Dogwalk® Medium wood-fitting door covers 5 to 36 mm; the Catwalk® cat door covers 11 to 30 mm.
Clip-in panels versus a fitted door
You will also see aluminium pet door panels that stand in the slider’s track. They avoid a glazier, but they take width off the doorway, they leak draughts around the edges, and most can be lifted out from outside. A door fitted in the glass keeps the slider’s full width, its seal and its own lock. If you rent, read our rental guide first; a glass-fitting door is also the easiest to undo when you leave.
Getting it done
- Measure your pet (shoulder height and the widest point) and pick the door size. Our measuring guide takes five minutes, or find your door with three questions.
- Buy the door first, so the glazier works from the real cut-out size and the installation sheet.
- Book a glazier. Any local glazier can cut or order the glass; see installing a pet door in NZ and what it usually costs.
- Fit the frames through the hole, then turn the 4-way locking dial through all four positions.
Prefer to buy in store? Catwalk® and Dogwalk® doors are also at Mitre 10 stores across NZ. Not sure about your glass? Email a photo of the door and the stamp in the corner of the pane to info@petnest.co.nz.
Quick answers
Can you put a cat door in an aluminium door?
Yes. The pet door goes into the glass of the aluminium door, not into the aluminium frame. A glazier cuts a round hole in single glazing, or supplies a new double-glazed unit with the hole already made, and the Catwalk or Dogwalk frame clamps through it.
Can you cut the aluminium frame for a pet door?
No. Aluminium door frames are hollow extrusions that hold the glass and carry the hinges, rollers and locks, so they should not be cut. Every Catwalk and Dogwalk glass-fitting door goes through the glass instead and leaves the frame untouched.
Which pet door fits an aluminium ranch slider?
A Slim Line glass-fitting door. Its low frame clears the slider's track and the fixed panel, so the slider still opens fully and locks. The Catwalk Maxi Slim Line suits cats and small dogs; the Dogwalk Intermediate and Medium Slim Line suit bigger dogs.
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