Steiner's architecture is characterized by a liberation from traditional architectural constraints, especially through the departure from the right-angle as a basis for the building plan. For the first Goetheanum he achieved this in wood by employing boat builders to construct its rounded forms; for the second Goetheanum by using concrete to achieve sculptural shapes on an architectural scale.[17] The use of concrete to achieve organically expressive forms was an innovation for the times; in both buildings, Steiner sought to create forms that were spiritually expressive.[18]
Steiner suggested that he had derived the sculptural forms of the first Goetheanum as spiritual inspirations.[19]