The plot of Tammela is one of the largest in Old Rauma; the surface area is 1774 m². Along with the current main building, there has been a utility building with a cowshed and a stable.
The main building of Tammela was built as a residential building with several apartments. The use and the structure of the building have been changed several times over the years.
The courtyard and the garden have been preserved simple with traditional Finnish garden plants. The courtyard is always open for visitors.