The research employed non-invasive methods to identify the historical wall décor of Knafkus’ bedroom. Using these techniques, it was possible to detect decorative elements hidden beneath paint layers without their removal, thus preserving later overpaintings that often disintegrate together with the original décor during cleaning. This methodological approach allowed for the precise identification of historical painting fragments and their spatial arrangement without damaging the surface structure. The results revealed the compositional principles of the earlier décor and its relationship with later layers. The study highlights the importance of non-destructive technologies for safely investigating and documenting complex historical interiors.