Isabella Eco-Home Experiment Station

Isabella Eco-Home Experiment Station, Isabella, Minnesota

High Performance Architecture

Designed and certified to meet the Passive House Institute U.S. (PHIUS) standard for building energy performance, comfort, and durability, the Isabella Eco Home is a net-zero-energy use home located within the challenging climate of northeastern Minnesota.  It is also a Platinum Certified, U.S. Green Building Council Leadership in Energy and Environmental Design (LEED) Home.


On a private site in the Boreal forest of northeastern Minnesota, the Isabella Eco Home takes advantage of the landscape’s glacial till and undulating topography.  Overlooking Lake Gegoka, the property is oriented for proper solar exposure and view.


Both the exterior and interior of the Isabella Eco Home were designed to meet the following criteria:

  • Generate more renewable energy than it uses
  • Sustainably manage the use of water
  • Waste nothing
  • Adapt to new conditions
  • Work symbiotically with all other living things
  • Eliminate toxins and pollutants
  • Add beauty to our world


The Isabella Eco Home building envelope includes super-insulated, airtight, and durable assemblies, including: R-60+ slab, R-60+ walls, and R-100+ roofs. The exterior doors and windows are also high-performance products with a .088 U rating (R14).


The mechanical systems include a Zehnder ComfoAir HRV with a pre-tempered heat exchanger for mechanical ventilation. There are 92 SUNDA Seido evacuated solar heat collection tubes that collect about 42 million BTUs over the year.  A seasonal storage system was created in what would have been a basement of the main living area.  It is essentially a crib for sensible heated storage, lined with 16 inches of expanded polystyrene (EPS) insulation.  This long-term storage heats to about 120 degrees over the summer; it is delivered to the home during the winter using pumped water through tubing installed in the floor of the home.  To manage the heat flow to its optimal levels, there is a small geothermal heat pump that allows this long-term storage of heat to drop down to 50 degrees.  This improves the efficiency of storing and using the heat.  There is a 12kw photovoltaic electric power generation system located in the garage, providing all the energy needed to run pumps, lights, and plug loads throughout the home.  A backup battery system makes this home operate off-grid when needed.