Dog Door for French Doors: 4 Installation Options & Costs

Yes, you can put a dog door in a French door, and you don't always have to cut the door to do it. Which method works depends on how your French door is built: one large pane of glass, lots of small panes ("true" French doors), or glass on top with a solid panel below.

This guide covers the 4 ways to add a dog door to a French door, how to tell which one fits your door, and what each costs.

The short answer

• One big pane held in by a plastic frame: swap in a French door glass panel with the pet door already built in. No cutting of the existing glass or door may be needed, and you can often reinstall the original glass later. Professional glazing may be appropriate.
• One big pane, any frame: have a glass shop make a new pane with an in-glass dog door fitted in it.
• Many small panes (true French door): a custom pet door replaces one pane, or more for a bigger dog.
• Solid panel at the bottom: a door-mount dog door can go through that panel, the same way it would in any exterior door.

The 4 options side by side

First, figure out which French door you have

1. Count the panes. One big sheet of glass, or a grid of small panes? Grids are either real separate panes ("true divided light") or one pane with a decorative grille on top. Tap the glass in two squares: if a grille sits on the surface or between the layers, it's one pane.
2. Look at the inside of the glass. Many modern French doors hold the glass in with a plastic frame that's screwed on and sits higher than the door surface. That's the kind a glass panel swap is made for.
3. Measure the glass. Write down the width and height of the visible glass and its thickness.
4. Check the bottom. If the door has a solid panel below the glass, measure its height and the door's thickness (most exterior doors are 1 3/4").

Not sure? Send a photo of the inside of your door to support@puppyfeverpro.com and we'll tell you which option fits.

Option 1: Swap the glass for a panel with a pet door built in

For compatible doors, this can be one of the simplest ways to get a dog door in a French door. Security Boss builds a new dual-pane glass panel with the pet door already installed. The original glass unit is removed and a compatible replacement installed, following the manufacturer's glazing instructions. Nothing on the door is cut, so you can keep the original glass and put it back if you move.

• Fits: French doors whose glass is held in by a plastic frame, with glass that measures 21.75" x 65.75" or 23.75" x 65.75".
• Pet door choices: SB Standard, MaxSeal, MaxSeal PRO, a PetSafe electronic door, or an Animate cat and dog door.
• Price: $1,260 to $1,864 for the complete panel, depending on the pet door and size.

Good to know: it costs more up front than an in-glass door, but it may avoid a custom glass fabrication charge, though professional installation may still be needed.

Option 2: An in-glass pet door fitted by a glass shop

If your French door has one large pane but doesn't fit a ready-made panel, a local glass shop can make a new pane with an opening and fit an in-glass dog door into it. Tempered and dual-pane glass can't be cut after it's made, so the shop makes a new pane rather than cutting yours.

• Glass thickness: Security Boss in-glass doors fit glass 1/4" to 1 1/2" thick using a 1" or 1/2" adapter.
• Models: MaxSeal In-Glass (from $247), MaxSeal PRO In-Glass (from $249) and the Standard In-Glass. All lock with a security panel.
• Sizes: up to 15.75" x 32" for giant breeds.

Good to know: add the glass shop's charge for the new pane and fitting. Cost guides put installed in-glass and French door pet doors at roughly $350 to $1,000 (see cost below).

Option 3: Replace one pane in a true French door

True French doors have separate, individual panes. In some designs a custom pet entrance may replace one pane, provided the opening safely fits your dog. Larger openings can require structural changes, which should be reviewed by a qualified door specialist. Never cut a rail, stile, or other structural member without confirming the door can support the modification.

Important: replacing a single pane may be reversible, but changes to the door frame often are not. Check glazing requirements and door warranties first.

These are made to order to your measurements. See custom French door pet doors and request a quote.

Option 4: A door-mount dog door in the bottom panel

Some French doors have glass on top and a solid panel at the bottom. If that panel is tall and wide enough for the opening, a regular dog door for doors can go through it, just like a standard exterior door.

• Door thickness: Security Boss door mounts fit doors 1 1/4" to 2" thick.
• Space: Security Boss recommends keeping the cut-out at least 3" from the edge of the door to keep it strong, and the opening has to stay below the glass.
• Models: SB Standard Door Mount (from $181), MaxSeal Door Mount (from $229) or MaxSeal PRO for Doors (from $238).

Our guide to installing a dog door in a door walks through the cut.

Which option should you choose?

• You rent, or don't want to cut anything: the glass panel swap, if your door fits it. You can put the original glass back.
• You have one big pane that doesn't fit a ready-made panel: an in-glass pet door through a glass shop.
• You have a true French door with small panes: a custom pane-replacement pet door.
• You have a solid bottom panel and want the lowest cost: a door mount.
• You live somewhere cold or windy: pick a MaxSeal or MaxSeal PRO pet door with a dual flap, whichever method you choose.

If your French doors open onto a patio that also has a sliding door, a sliding glass door insert may be simpler still: it stands in the track with no cutting at all.

How much does a French door dog door cost?

French door dog door pricing varies widely by glass type, the door model, the pet opening size and professional labor. A complete replacement glass panel can cost more than general installation averages. The amounts below were listed for Puppy Fever Pro products when this article was prepared; check current product prices and get a glass-shop quote before ordering.

• Glass panel swap: $1,260 to $1,864 for the panel, and no installer.
• In-glass: the pet door (from $247) plus a glass shop's new pane and fitting.
• Door mount: the pet door (from $181) plus a handyman if you don't cut it yourself.

Need someone to install it? We can arrange a professional installer anywhere in the US. Call 737-215-3211 or email support@puppyfeverpro.com for a quote. For the full breakdown, see how much it costs to install a dog door.

How to size the pet door

Measure your dog's height at the shoulders and the widest part of the chest. Compare these measurements with the manufacturer's clear flap opening, not the outside frame dimensions. Check the recommended head clearance for that particular product and keep the bottom low enough for your dog to step over comfortably, especially for puppies or older pets. With more than one pet, size for the largest and check the step-over for the smallest.

Frequently asked questions

Can you put a dog door in a French door?

Yes. You can replace the glass with a panel that has a pet door built in, have a glass shop fit an in-glass pet door, replace one pane in a true French door, or install a door-mount pet door in a solid bottom panel.

What is the best dog door for French doors?

For a door with one large pane in a screwed-on plastic frame, a ready-made glass panel is the easiest and can be undone. For security and cold weather, choose a MaxSeal or MaxSeal PRO pet door: both have insulated flaps and a locking security panel.

Is there a temporary dog door for French doors?

Not in the way there is for sliding doors, because French doors swing open. The closest option is the glass panel swap: you keep your original glass and can put it back when you move out.

Can you cut a dog door into tempered glass?

No. Tempered and dual-pane glass can't be cut after it's made. A glass shop makes a new pane with the opening built in, and the pet door is fitted to that pane.

Can you put a dog door in double-pane French doors?

Yes, but a sealed insulated glass unit generally must be replaced with a new unit made specifically for the pet door. Do not cut an existing sealed or tempered glass panel.

Will installing a pet door affect my French door warranty?

It might. Ask the door manufacturer or installer before changing the glazing or cutting a solid panel.

Will a dog door make my French door less secure?

Check the locking cover supplied with your chosen Security Boss model, and secure it when appropriate. The security of the French door, locks and surrounding glazing matters too. See how to secure a dog door for more ideas.

Get help choosing

Send us a photo of your French door and your dog's height at the shoulders. We'll tell you which option fits and what it will cost. Email support@puppyfeverpro.com or call 737-215-3211.

Shop in-glass and French door dog doors, or see all Security Boss dog doors.