2005 Renewable Energy in Buildings Award
Fossil Ridge High School, Fort Collins
Snowmass Golf Clubhouse
Missouri Heights Residence, Carbondale
Passive Solar Pop-Top Retrofit, Boulder
 
entrance to the Missouri Heights residence in Carbondale.

The front entrance of the Missouri Heights Residence is elegant yet understated in a way that gives no hint that this is a high-tech, superbly designed solar home.

Credit: Pat Sudmeier

Missouri Heights Residence

The Missouri Heights Residence in Carbondale, Colorado, is the winner of the CRES 2005 Renewable Energy in Buildings Award in the category of residential construction.
 
bullet Use of renewable energy
bullet Low environmental impact
bullet Winning design team

The Missouri Heights Residence is a home with a very high solar fraction of 85%, which means it obtains almost all of the energy it needs from the sun. There are some homes in Colorado that obtain 100% of their energy from the sun, but that usually costs extra for energy storage, etc. The owners of this house work at home and sought to create an environmentally friendly residence that could be constructed within their budget. According to their calculations, they built this home at a cost that was “very competitive” with that of conventional homes built in Carbondale.
 
Kitchen-dining area of the Missouri Heights residence in Carbondale.

Because the solar and energy storage features of this home are included in the structural design of the building, it is possible to be in this home and not know it is heated almost entirely by the sun.

Credit: Pat Sudmeier

Use of Renewable Energy

There are a number of very innovative design features of this home, including passive solar design and a greenhouse, which together comprise the primary heat source. To make this work, concrete floors and two-foot thick cast-earth walls create a thermal mass that stores heat energy when the sun is shining for later use. Thermal mass tends to moderate indoor temperature fluctuations year round and is a critical element of solar design. The concrete floors have pipes installed in them for radiant heating. When the sun is shining, a pump moves fluid through the floors to distribute heat energy of the sun through the floors.

The owners report that the temperature swings 5 degrees Fahrenheit (F) from warm weather to cold weather, which shows that the solar design and thermal mass are working well together.

Backup heating is from a natural gas fired high-efficiency boiler, which also provides backup heat for domestic hot water. Solar hot water panels on the roof supply the majority of the energy for heating domestic water. The walls are straw-bale construction with an R-48 high insulation value.

The home takes advantage of natural ventilation and daylighting. There is no air conditioning, and the owners report that summer indoor temperatures were 73 F when outdoor temperatures were 90 F. General lighting is with compact fluorescent fixtures.

For electricity supply, the owners installed a PV system rated at 1.8 kW on the rooftop that connects with the local utility, Holy Cross Electric Company, through a single meter (called net metering). The PV system supplies about 40% of the total electricity consumed in the house. The owners also purchase 100 kWh per month of electricity from Holy Cross under the company’s green pricing program, Wind Energy Pioneers.
 
Missouri Heights residence in Carbondale.
Native plants and trees surround the Missouri Heights Residence, which allows the structure to blend beautifully into the semi-arid mountain landscapes around Carbondale.

Credit: Pat Sudmeier

Low Environmental Impact

The designers took a number of steps to reduce the environmental impact of construction. They chose low-maintenance building materials that were obtained locally and compatible with natural surroundings. The house is framed with FSC certified lumber. A whopping 99.8% of construction materials were produced in the United States, most of this from nearby Carbondale. There are lots of recycled materials, including metal for roofing, reclaimed wood siding on the garage, and master shower tiles made from recycled glass.

The owners paid special attention to landscaping and gardening. They located the house on an old road cut nestled in a juniper and pinon grove that protects the structure from winter winds. Ground disturbed during construction was replanted in native grasses and wildflowers. A rooftop garden increases ceiling insulation to R-57 and reduces water runoff during rainstorms.

Winning Design Team

The design and construction team was led by Graybeal Architects, LLC, in Carbondale.
The other partners involved were:

  • Resource Engineering Group, Inc.
  • White Horse Consultants, Inc.
  • David Nelson & Associates, LLC
  • Wolf Brand Construction, Inc.
 
 

 

 

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