Hundertwasser follows in the tradition of the Viennese Seccesionstil which was the Austrian expression of the French Art Nouveau and German Jugendstil, continuing their purpose of employing art as decoration. His richness of surface and use of color suggest Klimt, while his scrubbed brushstrokes and moldy colors are reminiscent of Schiele. Hundertwasser's painting has been described as heavy, rigid, archaic and primitive. It is ironic that his deep awareness of the need for humanistic primitivism stems from a high degree of intellectual sophistication. This primitivism has been seen mostly through his use of color and line.
Hundertwasser can be considered a "colorist" painter, as color is an essential, if not overriding element of all his work. He uses highly saturated colors regardless of subject matter. He often paints while "on the road", using a pocket watercolor box or powdered pigments. He also frequently employs egg tempera, adding metallic dust; cloth or paper fragments; earth, ground glass or pottery; and finishing the piece with a thin glaze of oil.
Hundertwasser uses the six spectral colors almost exclusively, with no particular predilection for any one. His use of color is bold, and he has a strong sense of which colors work well together. Although he does not solely use traditional combinations, Hundertwasser's work exhibits frequent use of complementary color schemes. He clearly understands and employs color theory yet has expressed an intense dislike for all art theory.
Hundertwasser is also attracted by the colors of decay. He finds the colors associated with mold to be an expression of the living nature of inanimate objects, particularly buildings. He finds that mold adds to the beauty of structures.
Spirals are the primary shapes in Hundertwasser's paintings. They can be seen both literally and figuratively in most of his work. Hundertwasser felt that other artistic movements had "destroyed all forms . . . it was necessary to give oneself new rules and forms. Only one of these forms is worthy of confidence - the one that corresponds to the motion which is made when opposites begin to move. This movement is the spiral."
Although Klimt shared his interest in spirals, but Hundertwasser's spirals stray from the exacting mathematical form and thin line of Klimt's. Hundertwasser gives both line and form equal emphasis. The spiral is irregular in shape, and although both helix and core are maintained, neither is given more significance. Hundertwasser's spirals also defy the categorization of spiraling inwards or outwards, leaving the viewer wondering if the relationship is centripetal or centrifugal. Spirals have been described as Hundertwasser's way of beginning a painting when no other form comes to mind - a convenient receptacle into which other forms might be introduced. Hundertwasser has described spirals as "a bulwark for myself against my environment." He sees himself as the core, simultaneously protected and isolated by the surrounding cell or enclosure.
Hundertwasser believes that within each of us is a compilation of memories, sensations, images, dreams and wishes, which he calls an "Individualfilm." In his opinion the role of art is to bring this material to a conscious level.
Hundertwasser's architectural style shows the influence of Antoni Gaudi's work in Barcelona as well as some Jugendstil architects. This can be seen in Hundertwasser's inclusion of irregular almost accidental forms in his building design. Hundertwasser expresses an antipathy to severity and austerity in architecture which he sees in the use of straight lines. This may be a reaction to his surroundings, as Viennese architecture is marked by its strict structure and form.
Hundertwasser feels that "our present, planned architecture cannot be considered art. Our modern buildings are detached and pitiable compromises by men of bad conscience who work with straight-edged rulers."
Hundertwasser views building only as true architecture if its control is in the hands of an architect/mason/tenant. That is, the tenant should be directly responsible for the planning and implementation of building their domicile. "Unfortunately the building process ceases at the very moment when man takes up residence in his domicile; ideally, the building process should begin only when man moves in." Some of Hundertwasser's favorite forms of architecture are found in slums, where inhabitants have built their homes out of any materials they could find. "Everyone should make his own architecture, he should be able to construct what he likes, with feathers, grass or paper, even if the building collapses."
Hundertwasser's revolutionary architectural ideas also include topping buildings with trees and areas where animals can graze, and creating floor surfaces that are unlevel. Hundertwasser has designed many buildings in Austria and around the world, including museums, schools and churches, and continues to gain notoriety for his radical philosophies and outrageous antics.