In the archive there is no floor and wall, there is only a fireplace with accessories. Unfortunately, I did not find the developer's site, according to some information the fireplace is Iranian and make it exclusively to order to your size and needs. I made it for CNC machines, but it can also be used in projects.
Fireplace overall dimensions
height 1100mm
width 1900mm
depth 400mm

For all objects to be smoothed, one modifier is assigned. Those. you can easily adjust the degree of anti-aliasing of all objects through one (in the viewport, anti-aliasing is disabled).