The building site at the Birchsteg is characterised by the SBB railroad tracks cutting the plot, and by the surrounding traditional row housing in the Birchstrasse. With its massive, polished and slightly deformed appearance the building block reacts on the issue of local sound pollution. A central core -containing staircase, elevator and bathrooms- penetrates the whole building volume defining the adjacent open, split leveled spaces in different zones for living, sleeping and working.