Campo Cielo, Honduras, 2004
Campo Cielo is a sort of club room for women realized in Tegucigalpa, Honduras, 2004 by Andreas Froese. It offers shelter for about eight people. The building has an integrated water tank which required that cement had to be used in order to protect the earth mortar from water.
Froese usually does not apply cement in the walls of the buildings, but rather relies on earth mortar to stick the PET bottles together (see for example also the Trivadrum Cerala in India on this page).