Building the new permanent empire has started

The building of my new permanent layout empire has started. The preparation of the physical site, the layout room has started. The planning of the new layout is in a good position, so now the building of the background and roof has started.

I want to have no sharp corners between the background and roof, so in the corners I use paperpipes to mold concrete columns in, diameter 20 cm, that have been cut in 4 parts, each forming a 90 degrees curved element, to be placed in the corner, between the roof and walls.