The competition for a new county hall in Strasbourg, France was for a site located southwest of the town on the bank of the river Ill, exactly where historic Strasbourg meets 20th-century Strasbourg (embodied in the slabs housing the medical faculty). The site lies on the boundary between two types of urban planning, one emphasizing the traditional perimeter block, the other reflecting the ideology of large postwar developments, in which each building is treated as an isolated entity. Rather than imitate either of these, we adopted a conceptual framework that would create a new relationship between these different architectural types and offer a strategy that could be applied to similar situations. We decided that the nature of the competition site as a meeting point between old and new would justify rehabilitating the old barracks and suggest a new urban project that would clarify the relation of the historical fragments to today.