My little 5 pound Yorkie is not very athletic. He does run around quite a bit, but he will not jump very much. He needs help to get on the couch, chair, and bed, and when we moved to a new place, he would not go in and out of the terrace door to the back yard because of the small jump. So, I took matters into my own hands and made him a way to get through the door without hurting himself.
Step 1: Step 1: Materials and Measuring
It may not seem like much, but from a dog's eye view, this is quite a jump. I didn't even use a ruler. I had some 2x2 pieces of lumber that were the same length from another project around the house. I used those for the base, and found some 2x1s for the upper step. We also had some flatter boards that were just the right width for a couple steps.
Step 2: Step 2: Putting It Together
It would have been just as easy to use hammer and nails, but I prefer screws. So, using my trusty battery powered drill, I lined up the edges of the lower board with the very back of the 2x2s. I tacked it down really quick to make sure everything would stay in place. I then put the lower step against on the deck against the door frame. Using this as a place holder, I put the upper supports in place, held them together with a smaller screw, then used long screws to put everything together. My wife found us an outdoor mat so we could wipe our feet coming inside.
Step 3: Step 3: the Test
It took some convincing because our guy had taken a tumble or two trying to jump in and out of the house. Once we got him used to it, he started going up and down with ease. It is even strong enough to hold everyone in the family as they go in and out.
For anyone looking for a more permanent fixture, you could mount it to the deck, but it doesn't slide on ours (plus it's a rental). I might also suggest putting some kind of weather proof stain to make it look better, but it has served its purpose for a while now, and we haven't had any complaints.