This small wooden piece confused me for a bit. It seemed like a piano part, but it’s actually a raised section of the floor.
The instruction photos show the location of this piece
incorrectly, so refer to the finished photos of the dollhouse in the
back of the instruction booklet to ensure you place it correctly.
Notice that the front and side walls are glued together and then
attached to the first floor. Use the flooring as a guide to align your
walls. The hardwood represents the interior of the dollhouse, while the
wooden planks are for the exterior porch. Run the electrical wires
through the holes in the flooring.
Finally, install the last wall with the hinged panel.