Der Rote Faden (the red line) is a German phrase (Goethe „Elective Affinities“) that refers to a track, a path or a guideline. A Roter Faden connects distant things that belong together.

The building in Saalgasse 18, Frankfurt, by architect Charles Moore and Norbert Moest, is an example of an emotional and pluralistic post-modern architecture. The two houses are in reality just one. A red light tape joins the two seemingly different house-halves and repeats in it’s movement the circular elements of the architecture.