Virginia Law

Glass, fiberglass, or other glazing materials, framing members, and foundations used to enclose south facing areas such as patios, atriums, or greenhouses for purposes of entrapping solar heated air shall be considered solar energy equipment, provided that the warm air be circulated through the principal structure by use of a permanently installed air movement system (forced or convective) and that adequate provisions have been made to prevent nocturnal heat losses and cold weather heat losses through use of insulating devices. Fifty percent (50%) of the invoice cost of labor and materials used in constructing a greenhouse or similar type structure, are to be considered solar heating equipment. The greenhouse is serving two purposes: (1) that of a solar collector, and (2) as a means of growing flowers or other plants. Equipment such as ductwork and fans used in circulating solar heated air accumulated within enclosed south facing areas such as patios, atriums, or greenhouses shall be considered solar energy equipment up to the point where such a system is integrated with a conventional heating system. Full credit will be allowed for movable insulation used to reduce nocturnal and cold weather heat losses.

EXAMPLE: Mr. Jones enclosed his south facing patio with fiberglass panels and movable insulation for the purpose of entrapping warm air which accumulates beneath the glazing. The warm air is then circulated through the residence using permanently installed ductwork and fans independent of his conventional heating and cooling system. The fiberglass, movable insulation, fans and ductwork Mr. Jones used in his solar heating system are considered solar equipment and eligible for tax exemption.