cut out the slits of the (1) and fold. Fold the ends of (2) glue them together. As same the (3).

Paste (2) to (1), next paste (3) to one. The width of the tabs for sticking are different, so check the orientation.

Bend the bottom edge of (2) and apply glue there...

Press it flat and glue it.

Paste (4) to the chimney (3). Note the orientation of the parts. Align by looking at the crease.

Also paste the other side of (4) to the chimney (2).

Now paste the roof and (5), but first bend the tab on the top of (5). (all three)

For alignment, mark with a pencil about 11.5 mm on the left and right.

Align (5) with the pencil marks. Paste the bottom edge of the tab of (3) and the bottom edge of (5) together.

Paste the upper tab of (5) to the back side of the roof.

(6) and (7) are folded and glued together.

Then, paste (7) to the back side of (6).

Paste one of the tabs of (6) to the top edge of (5).

Fold (8) and (10), and make a cut at the crease.

Paste (8) to (5).

Paste (9) to (8).

Paste the tab of (6) to upper edge of (9).

Paste (10).

Flatten it by pressing, and paste the roof to the upper tab of (10).

Paste the house to the base (11). First paste (7) in the center, but before sticking, check that the tabs under the wall and the slit match.

Paste all the tabs at the bottom to the base.

(12) and (13) are folded and glued together, and then paste them together.

(14) and (15) are folded in half and glued, and then paste to (12) and (13).

like this.

Paste it to the base.

The inside parts are now complete

Paste colored paper to the outside. If you make it slightly larger than A5 size, you can leave it as a border decoration. (In that case, trim the edges so that the width is even.)

I trimmed it without leaving any margins. It's easier to use a steel ruler to trim the edges.