The new architecture has 'opened' the walls so that the separateness of interior and exterior is suppressed. Walls no longer sustain since the system… - Theo van Doesburg

The plastic expression of space is inconceivable without light. Light and space complete one another. In architecture light represents an element of plastic expression – in fact, the most important one. An organic relationship between 'space' and 'material' is possible only with the aid of light. The highest achievements in architecture can be accomplished only if light also is treated as plastic form.

In addition, 'Elementarism' is real instead of abstract. The use of the term 'abstract' also caused much misunderstanding. This is easily explained.. .As used in connection with visual methods of expression, the term 'abstract' is extremely relative. 'To abstract' something implies one of those mental activities (in contrast to emotional spontaneity) through which certain [aesthetic] values are isolated from the world of reality. However, when such values were realized visually and applied as purely constructive means, they became real. Thus the abstract was transformed into the real, thereby illustrating the relativity of the former term. Hence, the term ‘abstract-real’ [proposed by his former artist-fellow Piet Mondrian,] was a fortunate invention, although in reference to a new orientation [van Doesburg's new art orientation 'Elementarism'] the term 'real' is sufficient. The period of abstraction is at an end. Is not an elementary painting, which is to say a certain composition of plane-linear colours, organic in itself, more concrete...

Gradually we began [ De Stijl-artists in The Netherlands, 1918] to present a closed front. By working there had been created not only a clarity in the collective consciousness of our group, but we had gained a certainty, which made it possible for us to define our collective attitude towards life and to perpetrate it according to the requirements of the period.. .As the world war [ World War I ] was coming to an end, we all came to feel the need of securing an interest in our efforts beyond the narrow boundaries of Holland.