Earthship Research: Kuil

Elena Kuil
The Sustainability of Conventional Houses, Passive Houses and Earthships, Based on Legislation, Environmental Impact Energy and Operating Energy. University of Groningen. 2012. Link to Complete Report pdf HERE.


“Europe is leading the world in its recovery and recycling of used tires, steel, and aluminum, nearing 100% recovery, thereby rendering tire walls, and the use of steel and aluminum within the building structure as a non-functional “sustainable” alternative for disposal.”

“…a conventional house has the lowest environmental impact. In passive houses more insulation materials are used, that, in general, have a higher environmental impact. In earthships, among others, a lot of dirt and clay is used that cause a higher environmental impact. The conventional roof scores the lowest. Possibly, this is due to the fact that in the conventional roof no EPS is used, in contrast with the conventional floor and roof. 

“The passive house mainly has a higher environmental impact due to the passive house floor. Furthermore, the passive house roof scores high ecosystems. It is striking that in both the roof and the floor sawn timber is used. This might explain the high environmental impact on ecosystems. The environmental impact of the floor… seems to be caused by the use of OSB. Concrete, EPS and cellulose fibre cannot be the cause of the peaks. Concrete shows no peak for the floor in the graph of the conventional house and the earthship. EPS shows no peak for the floor of the conventional house. Cellulose fibre is used in the floor, wall and roof of the passive house.”

The Earthship has a high environmental impact for the wall and the roof. Probably the large amounts of clay and dirt in the wall have their influence. Furthermore, the environmental impact of the earthship roof is possibly high due to the use of rock wool and/or steel. The earthship floor scores relatively low with respect to the earthship’s wall and roof. However, note that the earthship floor scores higher when compared to a conventional floor. The difference can only be explained by the use of natural stone (which must be quarried) in an earthship floor. It should be noted that the environmental impact of the floor is even higher when insulation materials are used."

Based on the environmental impact alone, conventional houses are more sustainable than passive houses. Passive houses are in their turn, more sustainable than earthships. However, the general idea behind passive houses and earthships is that they recover the extra energy used for the production of building materials when the houses are in use. If passive houses and earthships have a higher energy efficiency than conventional houses once in use, eventually they will be net more economically favorable and are thus sustainable.”

“Although it is good ambition to reuse materials in an earthship, it is questionable whether all materials that are reused in earthships contribute to the reduction of the environmental impact. The glass bottles and the steel and aluminum cans are 100% recyclable. Therefore, it seems better to collect the bottles and cans and to reuse them to create new objects instead of reusing them as building block in an earthship.”

Reviewer’s Commentary:

Of particular note in this report is the lack of explanation of the divergence of Earthship Europe from traditional earthship design. Earthship Europe has modified the designs extensively, and their spinoff, Flagship Europe, walked away from the earthship concept entirely.

This research points to several resolutions we must find if the earthship ideals are to be realized. The chapter that addresses the issue in Part 2 of this book is listed after the issue if we address it:

Use of varied materials  – Enclosure: Walls
                                                   Earth-Coupling and Earth Sheltering 101
Understanding recycling  – Part 1: The Myth of Earthships and Recycling
and Part 1: The Myth of “A Radically Sustainable Home Made of Recycled and Natural Materials…”