Dog houses come in a variety of sizes, shapes and materials. Bigger breeds like Saint Bernards, Great Danes and Bull Mastiffs require a larger space to stand up and lie down comfortably (via CallingAllDogs).
Selecting the correct house size is key. A doghouse that is too small will be uncomfortable for the pet and will not retain body heat as well in chilly temperatures. A house that is too large, however, may allow the pet to lose their own body heat and can lead to moisture build-up.
Generally, the door height opening should be no less than three fourths of the dogs shoulder to ground measurement and the house length and width measurements should be at least 25% larger than the dogs nose to flank measurement (tails do not count) (via Classy Pet Shop). A good rule of thumb is to measure from the ground up to the top of the pets head for the standing height and for the body measurement, to multiply the pets length from the tip of their nose to their tail base.
Once the doghouse is built, a layer of asphalt-impregnated roofing paper or tar paper can be applied to prevent moisture from entering the house. Once the roof is secure, shingles can be added for an aesthetically pleasing look. The best large dog house will also feature a slanted roof to divert rain or snow away from the entrance. A large door, ventilation openings and a raised floor are also important features of a doghouse.