If you drive by Woodside St. on a Saturday morning, odds are you will see Spencer Dennis mowing his roof.

   Dennis is the owner of a slightly unique design of a house; it’s underground and completely made of concrete.  It appears to be of a modern style, but the house is actually 29 years old.   The houses’ construction ended in 1980.  Dennis had the idea of an underground house in his head for three years before it was put on paper.  He explains that the design was created to fix a wide variety of problems. 

   He designed the house with the idea to keep it environmentally friendly. 

   “Part of the idea was to build it environmentally integrated as much as I could,” said Dennis.

    The underground design minimizes the amount of water runoff.  It also greatly reduces the amount of energy needed to cool and heat the house.  Over the span of the last ten years, the average monthly heating and cooling cost were around 125 dollars for the 2,500 square foot home.

   The design was also built to moderate extreme temperatures.  Because the structure is completely underground, the temperature naturally stays cooler.  

   “Because the house is underground, the ground temperature affects the house temperature more severely;” said Marsha McClanahan, project administrator for the energy management and conversation department of City Utilities of Springfield. “The ground temperature stays around 60 degrees year round, therefore less energy is needed to heat and cool the house.”

   There is, however, one downfall to using a large amount of concrete. 

   ”The material concrete has a huge thirst for heat energy, so when someone walks into my home the concrete somewhat steals their thermal energy.  In essence, this causes people to feel slightly cold, even though the room temperature is moderate,” said Dennis.

   The design of the house protects the structure from the infamous Midwest tornadoes.  In 1991, a tornado passed through Dennis’ property, completely destroying the cars he owned at the time and ruining 42 trees on his property. His neighbors’ houses were damaged in different amounts, yet there was no significant damage to his own home.

   There are some things Dennis wishes he could change about the design. 

   “I wish the house was a little larger, and I would include a southern orientation if I could because it would generate more solar heat,” Dennis said.

   Also, because the house was built in 1980 some of the building materials are outdated.  For example, the house uses copper tubing, which causes a few energy deficiencies.  Plastic tubing is the more modern material, and is much better for efficient energy usage. 

   The house uses an unusual form of reinforcement, post tension cables.  Concrete naturally has a high compression, but it is somewhat weak in tension.  This is what causes it to crack when the ground moisture changes.  

   In his design, steel cables are made into a grid for support.  Post tension cables add to the strength of foundation slabs ensuring the house from leaks and other malfunctions.

   Since the house was built, there has been interest in the structure.  People have stopped by at random times just to ask him questions about it.  The interest seems to rise with the oil costs, when people get slammed with large energy bills.  

   “I know it is a structure that doesn’t meet with most people’s idea of a cozy environment. But I strongly believe there are real benefits to it”, said Spencer Dennis. “It opens doors to solving some problems, like material usage and disposal and will have a longer life than its surroundings.”