Step 1:
The papers are the same size for all three models and have a different color on each side.
Prefold in half over both lines.

Step 6:
Make sharper folding lines.

Step 5:
Fold over the prefolded lines.

Step 2:
Prefold both halfs in three parts of the same size, use the orange colored bar in this and the next picture as help.

Step 4:
Repeat step 2 and 3 in this direction

Step 3:
Both parts of the orange colored bar are the same size here.

Step 10:
This house model is done....

Step 8:
Fold the edge straight downwards, do the same on the backside.

Step 9:
Fold this edge straight downwards, do the same on the backside. Use glue or tape.

Step 7:
Fold both corners towards each other, see arrow.
Do the same on the left.

Step 16:
Fold the four corners inwards.

Step 15:
Fold the edges downwards.

Step 12:
Prefold over these two lines.

Step 11:
Repeat steps 1 to 4 on another paper.
Then fold over these prefolded lines.

Step 14:
Make four edges

Step 13:
Make sharper folding lines.

Step 21:
Make this folding line sharper.

Step 19:
And this house model is done too.....

Step 20:
Prefold another paper the same as in steps 1 to 4
Then fold over this line.

Step 18:
This is how the inside of the model looks.

Step 17:
Fold the four flaps in half.

Step 22:
Glue or tape into a rectangular tube.

Step 24:
Glue or tape both edges together.

Step 23:
Fold both corners towards each other, see large arrows. Repeat on the backside, see small arrow.