Can you put a dog door in a French door? Yes, if it is a true French door with several separate panes of glass. You take out one pane and fit a self-framing pet door in its place, sometimes cutting a little into the wood or adding a clear acrylic infill. A door with one big pane needs an in-glass pet door instead.
Here is how to tell which kind you have, the five ways in, and the cuts to avoid, based on Hale's French Door Model installation manual. Hale has built pet doors in the USA since 1985.
Can you put a dog door in a French door? Check the glass first
True French (multi-lite) vs. single-lite doors
The manual defines a "true French door" as one with several individual panes of glass, also called multi-lite. One pane comes out, and the pet door frame goes into the opening it leaves.
A single-lite door looks similar but has one big pane, and some are made to look like true French doors. The manual is blunt: the French door model "IS NOT usable for a single-lite door."
The glazier's-mark test
Some single-lite doors are, in the manual's words, "almost indistinguishable from a true French door." To check yours, look for an engraved glazier's mark in the corners of the panes. If there are many panes but only one glazier's mark, you are probably looking at a single-lite door.
If you have a single-lite door
For single-lite doors, Hale has an In-Glass Model, which the manual says "requires replacing the entire pane of glass." The product page lists French doors among its uses and says professional installation is required; it also says to check the rough opening sizing chart before ordering your glass.
Why not cut the existing glass? The federal safety glazing standard, 16 CFR 1201, covers glazing used in "Doors." Tempered glass is heat-treated safety glass, and glass maker Bendheim explains that it cannot be cut or drilled once tempered. So if your pane is tempered, the opening has to be built into a new pane.
Five ways to fit a French door dog door
The first four options all use the Hale Door Model, a self-framing door listed for multi-lite French, raised panel, hollow core, wood and metal doors. The manual calls that self-framing design "ideal for French door installation."
| Your door | Install type | Pet door size | What it involves |
|---|---|---|---|
| Solid lower panel below the glass | Standard Door Model install | Standard | Cut through the panel; no glass removed |
| Multi-lite, a pane matches your pet's size | F-1 | Custom | Remove one pane; pet door fills that opening |
| Multi-lite, pane too small for your pet | F-2 | Usually an in-stock standard size | Remove one pane and cut down or over into the door body |
| Multi-lite, pet door spans part of two panes | F-3 | Custom or standard | Remove one or more panes; fill the leftover gap with acrylic |
| Single-lite (one big pane) | In-Glass Model | Built into new glass | Replace the entire pane; professional install |
Solid lower panel
Some French doors have a solid panel below the glass. If it is big enough, a standard Door Model goes through it without touching the glass. Hale's Door Model manual says the rough opening should be no less than four inches from both the bottom and the side of the door. The Door Model fits doors 1 1/4" to 2" thick; call Hale about a factory cut-down or build-out for thinner doors.
F-1: replace one pane
An F-1 swaps one pane of glass for a custom size pet door that fills the same opening. To size it, measure the visible glass, width by height. Per the manual, that is your rough opening, so you order the door before removing anything.
F-2: one pane plus a cut into the door
When a pane is too small, an F-2 removes it and cuts down or over (or both) into the door body to fit a standard size. The manual says this "can usually be done with an in-stock standard size" door. For exact cut sizes, see our dog door rough opening guide.
F-3: an acrylic infill
An F-3 removes one or more panes (and the divider between them) and partially refills one pane with an infill, usually clear acrylic (Plexiglas). Layout matters most here (see below).
How a dog door for a French door goes in
The manual states that "any person with a working knowledge of power tools and basic home construction" can do the install. Lay drop cloths on both sides of the door and wear eye protection and gloves.
Kit contents: the Door Model, a security cover, 5/8" #6 Phillips head screws, a 7/64" drill bit, instructions and the warranty.
Tools you might need: razor knife, two putty knives, chisel, flat bar, hammer, finishing nails, level, drill, reciprocating saw, and a circular saw with a diamond blade.
- Find the removable molding. Look for staples or nail heads, or slide a putty knife under painted-over molding. For an F-2 door with no removable molding, the manual says to call technical support.
- Free the molding. Run a razor knife along its back edge to cut the paint or finish. Stack two putty knives under it and twist a flat bar between them to pry it off without breaking the glass.
- Remove the pane. Pull every nail or staple, loosen the glass (usually glued) from outside with a putty knife, and push it out. Wrap and label it with its molding in case you reinstall it later.
- Cut, if your install calls for it. For an F-2 or F-3, mark the cut, drill out the corners, then cut out the rest of the rough opening. On an F-3, cut the acrylic infill to fit now, leaving its protective paper on until fitting is done.
- Fit the frames. Set the inner frame (with the security cover tracks) in from inside, sleeve the outer frame on from outside, and snap them together. If you use the optional raincap, hook it onto the top of the outer frame first.
- Level and screw. Drill one pilot hole at the bottom with the supplied bit, set one screw loosely, level the door, then tighten and finish the rest. The manual warns not to bump any other panes with the drill bit. On an F-3, nail the molding back around the acrylic before the final screws, protecting the acrylic with cardboard.
- Slide in the security cover. It runs in the built-in track and locks with the positive-action pin lock.
Steel-skinned French door? See our guide to installing a dog door in a metal door.
Layouts and cuts to avoid
Where you cut matters as much as how. These rules come from the manual.
- Keep four inches of wood. The manual says: "Do NOT cut closer than four inches from the side or bottom of door." Some doors need more, and cutting closer weakens the door.
- Don't cut into both mullions. Good F-3 layouts use one full pane plus part of a second, running up, sideways or down into the door base. Avoid layouts that leave a narrow side or bottom piece, or that take one pane plus parts of two others, cutting into both mullions. Hale calls the result "a very weak installation."
- Score stained or varnished wood first. French doors are often stained and varnished wood. Draw a second line about 1/8" outside your rough opening and score it with a utility knife, so splinters stop there.
Three checks before you order
Before buying a pet door for a French door, confirm these. For location and climate questions, see how to choose the best dog door.
- The handle and the security cover. The manual says to consider whether the door handle would interfere with the security cover. The standard cover loads from the top; Hale can make it slide right or left at no additional cost if you add that to your order notes. Already installed and the handle is in the way? Call 1-800-646-4773.
- Door thickness. Measure it and compare with the Door Model's 1 1/4" to 2" range.
- Your dog's size. Per the manual, the top of the opening should be above your tallest pet's shoulder, and the shortest pet should not have to jump through. Hale's pet door sizing guide adds that the flap top should be an inch or two above the withers. The manual also notes that "Many French doors require a custom size pet door."
Not sure which install type fits? Hale offers free consultation with an experienced installer at 1-800-646-4773, or you can find an installer near you. You can also browse all Hale dog doors or compare door-mounted dog doors.
Frequently asked questions
Can you put a dog door in a French door with one big pane of glass?
Not with a framed door model. Hale's French door manual says that model is not usable for a single-lite door. The option is Hale's In-Glass Model, which replaces the entire pane of glass and requires professional installation.
Do I need a custom size dog door for my French door?
Often, yes. Hale's manual notes that many French doors require a custom size pet door. An F-1 install, where the pet door replaces one pane, uses a custom size: measure the visible glass width by height to get the rough opening. An F-2 install, which also cuts into the door body, can usually use a standard in-stock size.
Can you cut a dog door opening into the glass of a French door?
Not if the glass is tempered: according to glass maker Bendheim, tempered glass cannot be cut or drilled after tempering. Hale's approach removes the pane instead, fitting a door model into a multi-lite opening or replacing a single-lite pane with an in-glass model.
How close to the edge of a French door can you cut?
Hale's manual says not to cut closer than four inches from the side or bottom of the door, and some doors need more wood left than that. Cutting closer structurally weakens the door. On acrylic infill installs, also avoid cutting into both mullions.
Can I install a French door dog door myself?
Hale's manual says anyone with a working knowledge of power tools and basic home construction can install it. In-glass models are the exception and require professional installation, so use Hale's dealer finder for those. For a free consultation with an experienced installer, call 1-800-646-4773.
Sources
- Hale Pet Door, French Door Model installation instructions (PDF), halepetdoor.com/diy-installation-manuals/french_door_install_instructions.pdf
- Hale Pet Door, Door Model installation instructions (PDF), halepetdoor.com/diy-installation-manuals/Door_Model_Installation.pdf
- 16 CFR 1201.1, Safety Standard for Architectural Glazing Materials: scope (Cornell LII)
- Bendheim, "What is tempered glass? Is it safety glass?"
