All dogs spend at least some time outside.And if your dog is ever left outside when you're not home, then he'll need a doghouse or some sort of shelter.
Is Bigger Better?If a dog house is large enough for a medium-sized dog, like a Beagle, then it stands to reason it ought to be great for a smaller dog, like a dachshund, correct? Not necessarily. Bigger isn't necessarily better when it comes to a dog house. Dogs like room enough to move around, but not necessarily a lot of extra room. Instinct tells them to find a cozy spot that is warm, provides shelter from the elements, and is safe from predators. Plus it's easier for a dog's own body heat to keep the house warm if it's not too large.
What's the Perfect Size?The standard size requirements are that your dog be able to stand up, turn around, and lie down comfortably in his house. The door should be set off to the side, to help keep wind, rain, snow, and sun out of the house. The door only needs to be tall enough for your dog's shoulders to clear: he'll likely instinctively duck as he goes in anyway. Make sure the doorway is wide enough to accommodate your dog at his widest point, but not much wider. To get a basic idea of dimensions, start by measuring your dog's height from the floor to the top of his head (or ears, if they stand erect) and from the floor to his shoulder, his girth from side to side at his widest point (probably his shoulders), and his length from the tip of his nose to the base of his tail. There are a number of different formulas to the right size. However, if the height and the length of the dog house are about 1 1/2 times your dog's dimensions, you should be fine. A little less is okay, but don't get too much larger than that. The width should be about the same as the length of your dog (slightly larger or smaller is okay).
Some Extra TipsMany manufacturers of pre-made dog houses will give breed suggestions. You can use those as a guideline. Some manufacturers set guidelines by weight. Don't use this as your sole factor in determining the house to get. A short, stocky dog like a Basset Hound may weigh as much as a tall, lithe dog like a Greyhound, but their house specifications would be vastly different. The floor to the house should be raised two or three inches off the ground, especially if it will be sitting on dirt. This not only allows rain water to flow under it, it will cut down the dirt and insects that get in.