For sound guidance and tips for building a first-class dog kennel, we contacted Lisa Peterson, director of communications for the American Kennel Club. She gave us design advice and also mentioned some of the most common mistakes.
We were hoping to get a sizing formula. But it turns out there's no such thing. Kennel sizing is based on how much time your dog will be spending in the kennel and how much room you have to spare. If your dog is going to be outside all day, he needs a larger kennel so he can run and exercise. If you make it too small, he'll take every opportunity to “get even” with you and your neighbors with nonstop barking and other bad behaviors. So larger is better.
For walls and doors, chain link fencing is your best bet (4 ft. tall minimum, and taller if you have a larger dog). It's affordable and easy to assemble, and you can buy premade wall and door sections at any home center. Buy a spring-loaded “snap clip” to secure the swing-down latch (some dogs can figure out how to open those latches and escape).
If your dog is a digger, you'll have to embed a “direct burial” treated 2x12 below the fence. Or bury the fence itself about 1 ft. into the soil (see Figure A). Those methods aren't foolproof, but they'll usually prevent a “great escape.” Screen off any sides that face streets or sidewalks by sliding privacy slats through the fencing. That'll cut down on barking and overall stress.
When it comes to flooring material, concrete may seem like the best choice because you can slope it for drainage and it's easy to clean. But it's actually a mistake. The hard floor will, over time, cause calluses, worn pads, splayed toes and painful joints. Instead, Lisa recommends either large pea gravel (some dogs eat smaller gravel) or large flat stones (flagstone). The irregular shapes actually help your dog develop stronger paws. But before you throw down gravel or set the stones, take the time to install a sand base for drainage at least 6 in. deep if you're building on clay. Then lay down landscaping fabric to prevent weed growth. You'll probably scoop out gravel along with the poop, so it'll need replenishing every year. If you have enough space, the ultimate dog oasis is a grassy area within the kennel.
Several companies offer composite flooring materials for dog kennels. It definitely looks better than gravel and is easy to clean. But if your dog likes to chew things, it's not a good choice—unless, of course, your vet does free surgery. Plan on a surfaced path to the kennel. If you just have grass, you'll soon have a muddy path. All that mud will get tracked into the house.
Finally, dogs need protection from the elements. A doghouse isn't mandatory, but if you don't provide one, you should at least install a small roof and a windbreak. Dogs can withstand cold, but not cold and wind or rain. An elevated cot will get them off a freezing cold or searing hot floor. Even if you include a doghouse, provide other shaded areas in the kennel (landscape fabric stretched across the top works well).
When placing a doghouse, avoid the common DIY mistake of setting it in a corner (the roof is a perfect launching pad for a jump-over). Instead, locate it outside the kennel with an entrance hole cut through the fence. Or place it in the center of the kennel. If you're stuck with a corner location, make the fence higher in that area to prevent jump-outs.