The earth houses in Olst are inspired by Earthships by architect Michael Reynolds. The first Earthships date from forty years ago and have been extensively tested in use. Waste - where possible - and local building materials - as much as possible - are decisive in construction. An earthship is designed to be self-sufficient.

Architect Michel Post of Orio Architecten has adapted the principles to the Dutch situation (precipitation, annual temperature and subsoil).

12 houses have a north wall of car tires - filled with rammed earth - that partly supports the roof. In the 11 other houses we have replaced this with straw bales - the roof is leaning on a timber frame. The roof has a slope of 9º to optimally catch the sun: in the winter to the back of the house, in the summer little or no sun in the house.