In the late 1970s, Hundertwasser was asked by City of Vienna to build a housing project - housing for poorer citizens who could not afford it otherwise. Inside, there were wavy, undulating floors (""an uneven floor is a divine melody to the feet""), a roof covered with earth and grass, and large trees growing from inside the rooms, with limbs extending from windows. Hundertwasser took no payment for the design of the house, declaring that it was worth it, to prevent something ugly from going up in its place. Within the house there are 52 apartments, four offices, 16 private terraces and three communal terraces, and a total of 250 trees and bushes. The Hundertwasser House is one of Vienna's most visited buildings and has become part of Austria's cultural heritage.