The report recommends sub-slab depressurization systems design criteria to the State of Florida's Department of Community Affairs for their building code for radon resistant houses. Numerous details are set forth in the full report. Primary criteria include: (1) the operating soil depressurization system shall maintain under the entire building a static pressure less than the outdoor air static pressure; (2) suction shall be provided by a fan rated for continuous operation and having thermal overload protection with automatic reset features; (3) vent piping shall have a minimum slope of 1/8-in./ft (1.04 cm/m) in order to drain any condensation back to the soil beneath the soil gas retarder; and (4) suction points shall be equally distributed as follows: a maximum of 1300 sq ft (120.8 sq m) per suction point, each suction point located not less than 6 ft (1.3 m) nor more than 18 ft (5.5 m) from the perimeter, and multiple suction points shall be located within 36 ft (11.0 m) of each other. Documentation is presented in support of the recommendations.