Project Ouroboros south
Dennis Holloway, Rosemount, University of Minnesota, 1973



The Ouroboros Project took its name from a mythological serpent which would regenerate itself by eating its tail. Ouroboros represents a self-sufficient system, which was the ultimate goal of its architect, Dennis Holloway. In 1970, Holloway held a competition amongst his students at the University of Minnesota to design and build an experimental autonomous house (Holloway, “Project Ouroboros”). Ouroboros South was designed over a three year period and completed in 1973. In reality, Ouroboros is not fully autonomous, but more of an evolving laboratory for energy conservation and self-sufficiency. According to Popular Science correspondent in 1975 Sharon Marcovich, Ouroboros was “not a prototype of the house of the future, but simply a laboratory...an incredible educational opportunity for the students and public” (Marcovich. “Autonomous Living in the Ouroboros House”).

The three key tests Ouroboros undertook were solar collecting for heat, windmill for generating electricity, and a composting toilet with a sewage system for recycling waste. These key tests were accomplished through the 2000 square foot design in a trapezoidal floor plan, which aided Minnesota’s varying climate of hot summers and cold snowy winters. The longest wall faced south and was angled 60 degrees to maximize sun exposure. Earth from the building’s excavation was laid against the north, east and west walls to provide natural insulation. Natural ventilation was provided through the row of clerestory windows on the north side. A sod roof allowed evapo-transpiration, which removed the excess heat (Holloway “Project Ouroboros”). Not only does a sod roof provide good insulation, but its life expectancy is over 60 years.

One of the main goals of Ouroboros was capturing as much of the sun’s heat as possible. The first type of solar collector was called the open-flow trickle type collector created by Harry Thomason. This was found to be quite inefficient; therefore mechanical engineer student John Ilse designed a new type of solar collector. Ilse’s method involved the flow of water between two sheets of 24 gauge steel and is now known as the sandwich collector, two to three times more effective than Thomason’s method. Ilse’s sandwich method accounts for 67% of the projects heat load (Marcovich. “Autonomous Living in the Ouroboros House”). The solar collector was then improved a third time, due to minor imperfections on Ilse’s sandwich collector; the team improved the collector by replacing the framing on the glazing system with metal, and moving the storage tanks. There are now three storage tanks within the center of the house providing heat (Holloway, “Project Ouroboros”).

Another driver of Ouroboros South was the wind generator. A wind charger tower was installed by students under Allen Sondak, with a two bladed high speed propeller, 15 feet in diameter. This is connected to a five-kilowatt generator, providing 110 volts of direct current. The energy harnessed is stored in batteries in the basement along with the electric energy. Electricity is Dennis Holloway Rosemount, University of Minnesota, USA, 1973 still the main provider for the houses heat and running appliances. Ouroboros South’s last key experiment includes a flushless composting toilet, modeled after the Clivus Multrum in Sweden. Human waste falls into a large container in the basement, where it is kept for a period of six months to a year. Once this duration of time is up, aerobic bacteria begin consuming compost and turning it into safe fertilizer.

The entire project cost about $95,000, including student wages and served as a living experiment to autonomous living. In 1976 Professor Holloway was awarded the Environmental Quality in Science and Technology from the United States Environmental Protection Agency for his pioneering work on Project Ouroboros.

It is important to point out that in the early 1970s, close to the oil crisis, ecological discourse was manufactured in restitution of an already demised nature, as an artificial circular form of reasoning. In this logic, all living bodies and organic materials should be at the disposition and distribution of natural ends and reciprocal uses, in flux in the universe. The death of one thing should always be subservient to the restitution of another. Recurring restitution promised a new world that would recycle materials perpetually and feed all leftover substances back into cycles of production. The desire for the absolute purging of waste, or rather as suggested by Holloway, a house eating its waste articulates a deeply rooted eco-social fantasy for a world of no loss, by developing systems able to eat their own organic excretions..


KEYWORDS: Ouroboros, Sod Roof, Sandwich Collector




FIBERGLASS BLADE FAILURE: The fiberglass blade on the wind generator, designed by Allen Sondak, failed during one of Minnesota’s wind storms.

INEFFICIENT HEAT TRANSFER: Harry E. Thomason open-flow trickle type solar collector was very inefficient with heat transfer during Minnesota’s low temperatures.

HEAT STORAGE: The framing of the second solar collector designed by John Ilse was made from redwood, and the high temperatures burnt the wood. The heat storage was not as effectively surrounded by crush rock.