Big dogs are great. They’re basically sentient weighted blankets that shed. But man, living with a Great Dane or a Saint Bernard in a standard house is a logistical puzzle. You’re constantly playing doorman. It’s midnight, it’s raining, and your 120-pound fluff-ball decided he needs to bark at a literal leaf. That's usually when people start googling an extra large dog door.
But here's the thing. Most people buy these things like they're buying a pair of socks—just find the biggest one and move on. That is a massive mistake. When you cut a hole in your expensive front door or, even worse, your exterior wall, that's a permanent architectural decision. If you get it wrong, you aren't just out $200. You're looking at a drafty house, a skyrocketing heating bill, or a security risk that’s basically a welcome mat for a slender human burglar.
Honestly, I’ve seen people install these things only to realize their Mastiff won't even try to go through it because the flap makes a terrifying slapping sound. It’s loud. It’s heavy. And if that flap hits them on the way through? Good luck getting them to use it again.
The "Shoulder Height" Trap
Measurement is where everyone messes up. You’d think you just measure the widest part of the dog and call it a day. Nope.
The most critical measurement for an extra large dog door is actually the "rise." This is the distance from the floor to the bottom of the door opening. If you set the door too high, your aging dog with hip dysplasia is going to struggle to lift their legs over the threshold. If you set it too low, a tall dog has to hunch down in a way that’s bad for their spine over time.
You want the top of the opening to be at least an inch or two above the dog’s withers (the highest point of the shoulder blades).
Think about it this way: a Great Dane doesn't crawl. They walk. If they have to do a weird army crawl every time they want to pee, they’re going to start resenting the door. I once saw a homeowner install a door based on their dog's "head height." The dog spent three days staring at the door because he couldn't figure out how to navigate the flap without hitting his chest.
Measure the dog from the floor to the top of the shoulder. Then measure the width of the chest or hips (whichever is wider) and add two inches. That’s your minimum. Anything smaller is just asking for a stuck dog and a very expensive vet bill for a panicked animal.
Energy Bills and the "Wind Tunnel" Effect
Let's talk about the giant hole you're about to put in your house. An extra large dog door is basically a massive thermal leak. If you live somewhere like Minnesota or Arizona, a cheap plastic flap is going to cost you hundreds of dollars in lost AC or heat.
💡 You might also like: Cooper City FL Zip Codes: What Moving Here Is Actually Like
The "Value" doors you find at big-box retailers are usually single-flap. They’re flimsy. When the wind kicks up to 15 mph, that flap starts blowing open. Now you have a direct vent to the outdoors.
High-end brands like Hale Pet Door or Endura Flap use dual-flap systems. It creates a pocket of air—insulation, basically—between the interior and exterior. It’s like a double-pane window for your dog's butt. Endura Flap specifically uses magnets on the sides and bottom. It stays shut even in 50 mph gusts. If you’ve ever lived through a winter with a drafty dog door, you know that those magnets are worth their weight in gold.
Cheap flaps also warp. Sunlight hits the PVC, it gets brittle, it curls at the edges, and suddenly you have a half-inch gap where bugs and cold air just stream in. If the flap feels like a shower curtain, don’t buy it. It should feel substantial.
Security Concerns: The Human-Sized Hole
People worry about burglars. And yeah, an extra large dog door is big enough for a small person to crawl through. It’s a valid fear.
But here’s the reality check: Most burglars aren't looking to crawl through a dog door that likely has a 130-pound predator on the other side.
Still, you need a locking cover. Most doors come with a slide-in plastic panel. They’re okay, but a determined kick will pop them right out of the tracks. If you’re truly worried, look into steel security covers or doors that have a deadbolt locking mechanism.
Some tech-heavy options use RFID collars. The door stays locked until your specific dog walks up, then a motor slides the door up like a miniature garage. High-tech? Yes. Expensive? Extremely. These are great for keeping out raccoons or stray cats, but they have a failure rate. If the power goes out or the batteries in the collar die, your dog is locked out. Always have a low-tech backup plan.
Wall Mount vs. Door Mount
Where are you putting this thing?
📖 Related: Why People That Died on Their Birthday Are More Common Than You Think
Putting it in a door is the easiest DIY project. You take the door off the hinges, lay it on saw horses, cut the hole, and bolt the frame in. Done in two hours. But if you have a glass slider? You're looking at buying a whole new "insert" panel, which can be bulky and make the actual human doorway narrower.
Wall mounts are the pro move. They allow you to put the extra large dog door in a mudroom or a laundry room, tucked away from guests. But you're cutting through studs, siding, and drywall. You have to be 100% sure there’s no electrical wiring or plumbing in that specific bay of the wall.
Wall kits come with a "tunnel" that bridges the gap between the inner and outer wall. If you’re doing this, please, for the love of your house, caulk everything. If water leaks into the wall because you didn't seal the exterior frame, you’re looking at rot that will cost thousands to fix.
Training a Giant Dog to Use a Flap
Don't just shove your dog through the door. That's a great way to make them terrified of it forever.
Start with the flap off. Let them just walk through the open hole. Use high-value treats—think boiled chicken or smelly cheese. Once they’re comfortable, tape the flap up so it’s only halfway down. Let them feel it brush against their back.
Slowly lower it over a few days.
With extra large dogs, the weight of the flap can be intimidating. A heavy-duty rubber flap for a Great Dane might weigh a couple of pounds. To a dog, that feels like something is pushing back against them. They need to learn that they can win that "fight" by just leaning into it.
I’ve seen a Bullmastiff take two weeks just to get the courage to put his head through. Be patient. If you rush it, you’ll end up with a very expensive piece of wall art that your dog refuses to acknowledge.
👉 See also: Marie Kondo The Life Changing Magic of Tidying Up: What Most People Get Wrong
Material Choice: Why Aluminum Wins
Plastic frames are fine for Chihuahuas. For a dog that hits the door like a linebacker, you need aluminum.
Over time, a heavy dog will clip the sides of the frame as they fly through the door to chase a squirrel. Plastic will crack under that repeated stress. An aluminum frame, like those from PlexiDor or Pride, can handle the impact.
Also, consider the flap material. Some are made of "polyolefin" which stays flexible in the cold. Others are heavy vinyl. If you live in a place where it hits sub-zero temperatures, cheap vinyl becomes hard as a rock. Your dog will hit it, it won't move, and they'll think the door is locked.
The Raccoon Problem
It’s a real thing. If you leave your dog door "open" at night, you’re basically inviting the local wildlife for a snack in your kitchen.
If you don't want to spring for an electronic door, the best solution is a rigid "saloon door" style like the PlexiDor. These use heavy-duty springs to snap shut. They're much harder for a raccoon to pry open than a soft, flexible flap.
Otherwise, get into the habit of sliding the security panel in every single night when you do your final "house lockup." It’s a pain, but it’s better than finding a masked bandit in your pantry at 3 AM.
Actionable Steps for a Successful Install
If you're ready to pull the trigger on an extra large dog door, follow this specific sequence to avoid the most common "I wish I hadn't done that" moments:
- Tape the dimensions on the wall first. Use blue painter's tape to mark the exact size of the opening. Watch your dog walk past it. Does it look too small? Too high? This is your "sanity check" before you start cutting.
- Check for "Step-Through" clearance. If the door is going into a wall, make sure there isn't a rose bush or a steep drop-off on the other side. A dog jumping out of a hole and landing on uneven ground is a recipe for a torn ACL.
- Buy a "Tunnel Extension" if you’re going through a wall. Most kits assume a standard 2x4 or 2x6 wall. If you have an older house with thicker walls, you’ll need that extra piece of metal to bridge the gap.
- Weather-strip the frame. Even the best doors can have tiny gaps between the frame and your house. Use a high-quality silicone caulk on the exterior and foam weather stripping on the interior.
- Introduce the "Safety Panel" early. Put the locking cover on and off while the dog is watching. They need to understand that when the "solid" door is there, they can't go through. This prevents them from slamming into the plastic at full speed because they didn't realize it was closed.
Buying a dog door for a massive breed isn't just a purchase; it's a home improvement project. Don't cheap out. A $500 door that lasts 15 years is infinitely better than a $100 door that leaks air, breaks in two years, and makes your dog hate the backyard. Focus on the seal, the frame material, and the "rise" height, and you'll actually get to sleep through the night without being a full-time doorman.