Abstract: The "unmodified" roof (32) and "unmodified" attic (34), of a residential or similar building, are used in conjunction with an "attic based" air to liquid forced air heat exchanger (46) to form an active "attic solar energy vehicle". This solar (30) based system is used to heat swimming pools, spas, hot tubs, domestic hot water and in providing space heating/cooling and in cooling overheated swimming pools or other bodies of water--in a cost efficient way. Low operating cost forced air convection principles that make use of the temperature differentials present are applied. The "unmodified" roof (32) functions as a massive solar (30) collector. The "unmodified" attic (34) functions as a heat transfer and storage medium. The forced air to liquid heat exchanger (46) takes hot attic (34) air directly off of the interior of the roof structure (32) and transfers it to water or other liquid.