In 1949, Solar III returned to the ideas used in Solar I: heat collectors were located on the roof, this time tilted at a 57 degree angle to receive the maximum amount of winter sunlight. A 1200 gallon storage tank was mounted in the attic and solar heated water circulated through coils in the house's ceiling to provide heat.

Aesthetically more pleasing, Solar III was the first solar house to be used as a home, and was inhabited by a student family with one child. It caught on fire in December 1955 and the solar collector unit was destroyed. The house was demolished shortly thereafter.