Earth architecture Tierrafino Finish 95% Delphi 5% Ayers Rock, applied on walls of the town hall of Zutphen, Netherlands. For over 30 years now, there has been a real craze for ecological building in the public sector in the Netherlands. Banks, town halls, museums, administrative buildings, schools, cafés and even hospitals are being fitted with clay walls. Earth architecture have also found their way into many modern and historic private houses.