For KWK Promes, the traces of the past that were visible along the former slaughterhouse in Ostrava in Czechia weren’t blemishes. The Polish architects preserved the brickface facade, in disrepair and blackened by soot and made sure that historic and contemporary elements were clearly recognisable as such. All reconstructed elements, including a building wing in the south of the complex that was completely replaced, received a layer of microcement. In order to maintain the character of the brickface in the renovated existing structure, the architects repaired smaller defects by use of brick with artificial patina. They also opted for a ceramic screen print coating for the glass panes of the windows, providing them with a dark and matte impression.