Sorry to say, but that energy credit is only available for improvements to existing homes or can be claimed by the contractor of new construction.
"1) Requirements to Claim the Credit. A taxpayer may claim a credit under § 25C with respect to amounts paid or incurred for an item of property only if each of the following requirements is satisfied:
(a) The item is installed in or on a dwelling unit located in the United States and, at the time of installation, the dwelling unit is owned and used by the taxpayer as the taxpayer's principal residence (within the meaning of § 121). Thus, the credit is only available for existing homes. See § 45L for the credit applicable to new homes.
(b) The original use of the item commences with the taxpayer."
Internal Revenue Code:Sec. 45L. New Energy Efficient Home Credit can be claimed by the contractor of a new home.
"1) ELIGIBLE CONTRACTOR- The term `eligible contractor' means--
(A) the person who constructed the qualified new energy efficient
(B) in the case of a qualified new energy efficient home which is a
manufactured home, the manufactured home producer of such home"
I hope this helps to know the regulations even though you would rather have been able to claim this credit.