Here I have a small tutorial for everyone who don't know how to build
small parts.
First you have to cut all the pieces. As you see I prepared additional base that is
laminated to 1mm.
Now you glue the base to sidewalls.
Then you glue the other walls and the roof.
Now if you are an expert (you were able to cut and glue properly) you are done.
If you are not expert like me. You have still some job to do.
First you have to sink the part in superglue (cyanoacrylate). This makes the
paper strong as plastic. Now you have to polish up with sandpaper.
After all this the part is ready to be painted to your favorite color.