The Grand Hotel Thunerhof was built according to the plans of the Bernese architect Adolphe Tièche (1838-1912) on behalf of the construction company, Baugesellschaft Thun and opened in June 1875. The influence of the French castle design is clearly discernible and the dimensions are considerable: the main building is approximately 60 metres long, 30 metres wide and 20 metres high, with the dining room in front of it to the southeast.
As the first luxury hotel in the city of Thun, it came under bad weather right from the start. The project went over the budget even during the construction period. With 100 rooms and 200 beds, the hotel housed guests from around the world, and in its heyday was well known across the border. With the outbreak of the 2nd World War the operation of the hotel came to a standstill. In spring 1942, the property was acquired by the city of Thun. It was used initially by several institutions, businesses and as residential premises, and after conversion by the former city architect Karl Keller in the 1970s, the city administration also moved in. It eventually handed over the right wing to the museum. Since its inception, the Kunstmuseum has been existing on the premises of the Thunerhof. Today, the museum has more than 1,000 square metres of exhibition space.