Single Command Block Contraption - Auto building small office!

Some days ago, I found IJAMinecraft's amazing single command block contraptions. It was awesome. I wanted to learn how to do it. I tried but I couldn't figure out how to do it, until IJAMinecraft replied to my comment asking how to do it. He said "It's just a bunch of falling sand entities riding each other with special properties".
Then I got it. I started simple, but this is a bit more complicated than just simple. I mean, I managed to make a command block that builds a 5x5x5 small office with a worker included. I amimpressed with what I managed to do. And this is the result. is what you see here (you will have to bare with my building skills, I know it looks horrible).

HOW TO USE:
To use it, simply give yourself a command block by typing:
NOTE: In order to use command blocks, you need to have cheats enabled and be in creative mode!

Then, paste the following command into it.
Now, simply power the command block with a button!
PS - After running this, you get some extra quartz blocks!

You will soon get more and, hopefully, better!
All the credit goes to IJAMinecraft for inspiring me to do this.