Step 2: Making the door
If the DIY dog house you are working on is more rectangular (taller than wide), cut a 1-foot strip from two panels so that each remains a 3-foot x 4-foot section and arrange them so that the edge short across from you - make sure that when you cut the door, the position is high enough to allow the dog to enter the room without having to lower its head too low and low sufficient for you to cut the top.
The door's average height is around 24 inches, but make sure it is right for your dog and adjust as needed. Next, you will need to draw two parallel vertical lines - this will define the door's width. Twenty inches is usually the right size, but as usual, adjust as needed depending on your dog. Use a jigsaw to cut your door according to the measurements and signs you've taken. If you don't own a picture, saw or a circular saw, rent one from a home repair shop for a day!
