Make a cobblestone base

Add 19 more blocks so you have a 20 block high

Repeat next to it

Repeat the process and add 4 wood

Go to the same level as the cobble

Repeat the process

Build the roof of wooden slabs but leave 2 spaces

Add fences all the way to the top

Repeat on all sides

Go 3 up on every stack

Add a fence around the top

Make space for the door and add wooden floor

Add a door, ladders inside and a stair top! YOURE FINISHED