The lender’s permanent mortgage file must contain the following information to support the single close transaction, in addition to documentation outlined in this Handbook:

• Sufficient documentation to validate the actual cost to construct the subject home. (For example purchase contracts with the builder, Construction Loan Agreement, plans and specifications, receipts, invoices, lien waivers, etc.)
• Appropriate documentation to verify the acquisition and transfer of ownership of the land if the borrower acquired the land as a gift or inheritance.
• All HUD-1 forms and closing documents executed by all parties to the transaction and evidencing all costs to the homebuyer and property seller at the time of loan closing.
• If the land has been owned for less than 6 months at the time of closing, the complete and fully executed purchase contract for the land or other documentation to establish acquisition.

Additional Resource:  https://www.rd.usda.gov/files/3555-1chapter12.pdf#page=41