DeKALB | Conservation of natural resources has begun to take center stage in the minds of many.

A movement toward small ­— or what many would consider miniscule — houses has taken root, typically no bigger than a studio apartment .

One unique type of house is as small as 74 sq. ft. and makes use of a system of revolving rooms in which two or more rooms are on a turntable. The turntable hides the rooms that are not in use and exchanges them by use of a switch.

Other houses make use of solar power, recycled materials and mobility to help increase efficiency. Many people do not want to live in a space smaller than many family rooms, so some are introducing other ways to conserve resources.

DeKalb is also doing its part to conserve energy with an environmental test program involving geothermal energy. The program uses a system called closed-loop geothermal, which can both heat and cool buildings.

DeKalb ultimately is trying to set up four houses to use this system as a source of heating and cooling. Two houses already have the equipment installed and two slots in the study are still available.

“One is in operation, and one is in the final stages of permitting,” said Jerome Keys, chief building inspector for DeKalb.

The system circulates a mixture of water and anti-freeze that collects heat from the ground and is then removed from the mixture by a heat exchange pump. The pump then pushes the gathered heat through heating ducts throughout the building. The same system also can replace air conditioning, but with less efficiency.

The system DeKalb currently uses is not as complex as other systems because the loops through which the mixture travel go only 42 inches into the earth. The depth the pipes reach is dependent on the temperature of the ground in which the system is installed.

Other similar systems have pipes that reach more than 200 feet underground.

Keys said the city will survey data from the test sites. Whether ground contaminants are released into the environment by the system is one of the major questions these test houses can answer.