In the mid-19th century, master shoemaker Carl Degerman built a smaller residential building in the middle of the courtyard, which was demolished in the 1880s by copper manufacturer Lindfors to make way for a new one. The building is now called Mattila, after the museum's former caretaker. Originally, the building was likely constructed as a residence for two families. It was renovated in the 1980s to serve as the caretaker's residence, and it also housed the museum's office and storage space.

The building is called "Mattila" in finnish, which can't be directly translated.

Mattila still contains one of the two stove rooms in the Shopkeeper’s House Museum, which were common in the 19th century and even in the early 20th century, especially as working-class housing. Several layers of wallpaper from past decades have been found on the walls of Mattila's stove room.