Table of Contents -- Concerns -- Introduction -- The Five Houses -- The Logic of the Study -- Energy Impacts -- Graphic Analysis -- The Fisher House -- The Scott House -- The Wild River House -- The Bergstedt House -- The Humphreys House -- Comparisons -- Analytical Methods -- Base Data -- Analytical Strategy -- Comparisons -- Amount of Auxiliary Fuel Used -- Actual vs. Predicted Auxiliary Fuel -- Inferred vs. Predicted Passive Gain -- System Performance -- Range of Uncertainty -- Costs per BTU Saved -- 30 Year BTU Savings -- Postscript -- Bibliography.