I am building my dog a dog house and was wondering how big the interior should be. I have an average sized pit bull terrier, who is about 30" tall when sitting (from the top of her head to the floor). Right now I am thinking the W/H/D dimensions will be 36*32*36. I want to make it as I can though (without taking comfort from the dog). Do they actually sit up in the houses? Cause when she is standing, she is only about 24" from head to floor. Thanks for any advice.