Picking out the right dog house is a combination of choosing the right size, materials and insulation to fit the pet's needs. Used dog houses need to fulfill the same expectations as any dog house.
To determine if a dog house is the right size, the pet should be able to comfortably stand and nest in it without being crammed in. The doghouse does not need to be exceptionally large, as pets look for security and comfort when they are resting. A large house may lack the amount of insulation that a pet needs to stay warm in the winter and cool on hotter days.
Dog houses are typically made of wood or plastic. Both of these materials are equally suitable for adequate protection from the elements. Wood dog houses are usually more inexpensive but run the risk of termite destruction. Depending on the climate, humidity can also affect the longevity of a doghouse. A good used doghouse will show few, if any, signs of strain on wood joints, nails, nuts and bolts. If the doghouse is purchased locally, it will have already withstood local conditions, which is a good sign.
Plastic doghouses are typically waterproof. Check for signs of excessive chewing or broken joints that may compromise durability and insulation.