The use of a full scale solar hot water generation system is functioning in one building, which utilizes copper water lines thermally connected to the underside of the entire brown metal south facing roof of the building. This system captures any heat on the polycarbonate covered south facing section of the roof for heating water supplied for domestic use as well as radiant floor heating. On a Sunny day in the winter the system will generate a continual supply of 140°+water for the building needs. Due to the huge size of the system combined with a large tank and thermal storage capacity, very little if any supplemental heat is needed.