The Artist made this in chalk and crayon on white paper just at the end of the First World War. In this work clearly defined straight, jagged and curved lines overlay one another to form a pattern of angled planes and arcs that seems to suggest an urban setting. Several arches evoke the portals indicated in the title and the contrast between light and dark, produced by areas of dense shading against the white paper, are reminiscent of the effects of street lighting. Schwitters numbered many of his works sequentially and identified them according to type, as this one. The ‘Z’ prefix of Z 105 Portals of Houses stands for Zeichnung (meaning ‘drawing’ in German).