This tutorial shows you how you can easily create a working elevator with the help of command blocks, armor stands and boats in Minecraft version 1.9. It even works in 1.10+ exactly like that. For higher versions you'd have to adjust the commands a bit, but the gist of it should stay the same.
Just watch the video above to see how I did it. You can also find a download link down below, as well as all the commands I used in the video.
If you want the world file of the world I used in the video, you'll find the Download below. Make sure to open the world in any 1.9 or 1.10 version, but not 1.8 and lower, or 1.11 and higher.Download