The interiors of the House of Arts in Piešťany are an appealing visual interpretation of architectural thinking, in which the context with the surrounding landscape, composition of materials, architectural and artistic detail are inextricably linked. The concept, characterized by a logical, clearly legible spatial composition, has its natural reflection in the operational scheme and the interior architecture itself. The main representatives of the public spaces are the concert hall/great hall, the Hall of Mirrors/ballet hall and the small and large exhibition halls. The interiors of the hall spaces artistically compete with the arresting design of the foyer spaces located in their immediate vicinity.
The wheelchair-accessible concert hall with the capacity of 622 visitors is equipped with state-of-the-art theatre, film and sound equipment and a high quality lighting system, which make it possible to hold a wide range of events of various genres – concerts, congresses, film, theatre and other performances. In 2015, a complete reconstruction of the hall was carried out, preserving the original visual style of the interior. It included the replacement of carpets and the upholstering of wall coverings and chairs, thus offering higher ergonomic comfort for the audience. In addition to the design qualities themselves, the attractiveness of the hall space is enhanced by the presence of exceptional musical instruments in the form of a concert grand piano and a three-manual electric organ Rieger-Kloss made by Varhany Krnov. 
Compared to the relatively simple composition and the strict expressive monumentality of the architectural masses, the interiors are characterised by a greater playfulness of the building components. Spatial configurations based on blending, “branching” and linear overlapping of walls enrich the interior environment expressionally and perceptually, making it unique. The clearly legible essence of modern style is enhanced by large glazing panels generating attractive visual intersections and inviting visitors inwards. Materiality in the form of glass, raw concrete, wooden grid and slatted drop ceilings, studded flooring and white wall facing intensify the special atmosphere of the interior. The relatively austere effect of the building interior is given a warmer feel by the carpets and upholstered surfaces of the seating furniture designed using then characteristic arch shapes. The formative principles used and the timeless design seem in many ways as if they have predetermined later and contemporary trends, manifested in the dynamic linear articulation and rhythmically repeating structure of the surface materials.
The colour concept reflects the contemporary trends from that period, in which colour-dominant ceilings and accentuating furniture had their irreplaceable role. The colour palette used is limited to white, red, black and the natural colour of the raw concrete, which has contributed to the creation of a unified whole. The sections of the entrances to the main hall, conceived in a light-blue tonality, stand out from this concept. Despite the extensive use of red colours, the interior as a whole looks pleasant, which is also confirmed by Simona Pitoňáková: “I have to say that the colour that is used throughout the interior has a nice warm shade and its large surface area does not bother me at all, on the contrary. It perfectly complements the raw concrete, white facing and dark flooring.”  The resulting perceptual impact of the interior is significantly influenced by the dimension of natural and artificial lighting, perceived as an unmistakable artistic tool. A rhythmic, dynamic play with light, luminaires and ceilings can be seen along the entire building, visually culminating in the spectacular foyer space on the top floor, where the visitor’s gaze immediately rests on the large-scale artwork “Symphony of Man”, a celebration of the musical talent, musicality, grace of movement and harmony of man.