Directly Through Glass (Requires Glazier)

Yes, You Can Install a Pet Door Directly 'Through the Glass'

of your sliding glass door or window, sidelight or French door. While there are alternatives for most of these--you can purchase a patio pet door for your sliding glass door or undersized for your sliding window. And you can purchase a sash window pet door for your sash (up & down) window-the 'in glass' approach is less obtrusive, cleaner and neater. It's also more expensive and more trouble. So you make the decision between aesthetics, cost and convenience.

Here are a few tips we think important:

1. Use a Glazier - The glass in your slider, window or sidelight is going to be tempered and you can't cut that. The glazier will measure your glass, order a new piece--either single pane or dual--with a cut-out for the pet door and install it for you.  This is Not a do-it-yourself job!
2. If You've Got a French Door with Separate 'Lites' - You're in the wrong section. Remove one or more lites, cut down into the cross-piece if you must to make the step-over more manageable for your pet and order a custom dimension pet door to fit that opening. There's only one--Hale Custom for Doors--and on that product page you'll see an image of exactly what we're talking about here.. PS - Make really sure those are separate lites and not one big sheet of glass with moulding making it look like separate lites!
3. OK. You Can DIY and Here's How - Forget glass. You're going to use a piece of Lexan (generic name polycarbonate) cut to replace your glass and then cut a hole for a pet door in the polycarbonate. But note:
   1. The polycarbonate needs to be at least 3/16" thick or it's too bendy.
   2. Polycarbonate will scratch more easily than glass so this isn't good for a location, like a slider, that may receive some abuse.
   3. It's expensive as well so a window that isn't so large is a better choice than that big picture window.
   4. You can use a pet door designed to install in a door but if it's self-framing, and most are these days--be sure the thickness of your polycarbonate is in the adjustment range.
   5. If you want to go on the cheap, use plywood.