If you're thinking about buying a dog house plan, there are some things you need to consider before choosing one.
First, think about your local weather conditions. Does your area have very severe winters where the temperature can fall to zero or below and stay that way for a seek or more? How about summers? Do you have many days in the high '90s or even in the 100s? If you can answer "yes" to either of these questions, you will want to think about building an insulated dog house. On the other hand, if you live in a mild area such as Southern California, you may not need to worry about insulation in selecting a dog house plan.
Second, be sure to measure your dog, it's height and length -- so you can to build a dog house that will be the right size. If you build the house too small, your dog will be uncomfortable and may not want to use the dog house. Build it too big and your dog may not be able to stay warm when the weather grows chilly. Most of us like houses where there is at least two feet of air above our heads - in order to avoid feelings of claustrophobia. This comfort zone translates into about 1/3 of our standing height. You should allow your dog the same amount of airiness. Figure out how tall the dog is (or will be when fully grown) and then make sure the dog house ceiling or roof is at least 1/3 taller than this.
Third, when evaluating dog house plans, look for a plan that either includes a partial wall or is large enough that you can add a partial wall. This is so that the dog can escape the elements as necessary. If the weather is bad, the dog can choose to either sleep in the entry room or go around the inner wall into its "inner sanctum" to get warmer. Both areas could have bedding or a pillow such as a cedar-filled pillow to discourage fleas.
Fourth, look for a plan where there are hinges on the roof for easy cleaning - or a plan where it would be easy to incorporate hinges. When you clean the dog, make sure you also clean the dog house and bedding. After all, you would not want to sleep in a room that hasn't been cleaned for months or a bed where the sheets haven't been changed for weeks and your dog deserves to be treated the same way.
Also, be sure to consider your dog's habits. Some dogs like to sit on top of their house. If you think this may be true of your dog, don't put roll roofing or shingles on the top of the dog house since they can get very hot in the summer. Jus use an exterior plywood panel related with a nontoxic preservative like linseed oil. Also, you should probably choose a dog house plan with a slanted roof and not a peaked roof.
Since it's relatively easy to get free dog house plans, why would you want to buy one?
There are some good dog house plans available but there are also free dog house plans that can leave you scratching your head - with missing steps or illustrations that would make construction easier.
You won't have these problems when buying dog house plans because they must be good. After all, they must compete successfully with the free plans. Plus, you may have trouble finding a free dog house plan that you like and that will fit your dog.
Here are websites where you can buy dog house plans:
http://www.buildeazy.com/cfp_doghouse.html
http://www.luxurydoghouse.com/dog-house-plans.html
www.ashcustomwood.com/aboutthehouses.cfm