Redstone elevator

You're going to start by making walls for the elevator. The dimensions should be 4x4 and the height can be whatever you decide! Keep in mind that before you choose your building material, it will need to blend nicely with the stairs that we will add later on.
Add a block in the ground to show visitors where they need to stand in order to activate the elevator. I marked the ground here with a stone brick block.

Step 2 Button

After you finished building your walls, you will want to add a marker. This is where your button will be placed later on.

Step 3 Spiral Staircase

Next you will want to add your stairs. Stand on the marker you made earlier on the ground and face to your right. Place the stair there, and continue making the spiral staircase all the way up to the top.

 

[1] First stair placement, [2] Outside view, [3] First and second stair placement, [4] Third and fourth stair placement... continue this all the way up!

Step 4 Holes

You now need to add holes. These holes are just guidelines to show where the sticky pistons will need to be placed.
The way this elevator works, the sticky pistons push 1 block from the wall... which in return pushes the player literally right up—one stair at a time. Keep this in mind when making your holes, and that will ensure that you are placing your holes correctly!
When you walk through the front entrance of your elevator, look to the left of the marker in the ground. 1 block up from the ground (2nd block up), that is the first hole you will need to break. Continue breaking 1 hole all the way to the top of your elevator.

 

**NOTE: Keep in mind that the blocks are NOT going to be pushing the stairs, they are going to be pushing players up the stairs! **

Step 5 Add Blocks

For this step, all you need to do is add one block below each hole you just created in Step 4.
Keep in mind that you are NOT placing blocks directly behind the holes... you're placing them 1 block down below each hole you just made.
Again, do the same thing all the way up to the top!

 

Step 6 Sticky Pistons!

Go inside of your elevator tower, and place 1 sticky piston on each block you just placed in Step 5. The sticky pistons will be one block back. Look at the images below for reference!

Step 7 Cover Up!

You will need to go back into the tower and cover each individual sticky piston with 1 block. This is the block that the sticky piston pushes, and in return will push the player right up the stairs!

 

Step 8 Redstone / Redstone Repeaters

This next step might seem tricky at first, but I promise it's easy!
What you will need to do is place a block behind your button marker (our button marker is red wool). Place redstone on top of this block, and place another redstone 1 block down so that it charges the block below the sticky piston.
Next, stand to the left of the sticky piston, and face left. Look down, jump and place a redstone repeater. Make sure that the redstone repeater is facing left, otherwise it will not work. Set the repeater to 4 (right-click 3 times to the last setting). I personally like this setting, as it's the slowest. But feel free to experiment with faster times. If you like a faster elevator, change repeaters to 2 (1 click) instead of 4.

Continue connecting the sticky pistons to redstone and redstone repeaters all the way to the top. Make sure you are doing a stair-like method (the only option) along the outside of the elevator. Keep in mind that the redstone will always power the block BELOW the sticky piston—the redstone never actually is beside the sticky piston.