Minecraft – How to make a piston elevator

I think it may be because the piston extension NOT BASE does not count as a full block, but it depends what type of elevator.

To see if you are on a full block or not press F3(PC), there is something saying g:true/false (if its true you are standing on a full block)

One easy(ish) solution is to use a sand door. You can make them as wide as you would like, and about 3 high.

Here's one design that should work with the XBOX edition:

If you want to do some searching, what you want is a tileable triple piston extender for Minecraft 1.0.1. Or, if you only need it to be 2 high, then you only need a double piston extender, which is quite an easy design.