Direct answer
A complete closeout package includes manufacturer product data sheets showing R-value per surface, coverage area, square footage, and an itemized invoice separating insulation costs from any non-qualifying line items (demolition, drywall repair, HVAC modification). Cincinnati-area installers generate this automatically.
More detail
The closeout package matters for several reasons beyond any one tax program. (1) Resale value: Cincinnati MLS comparables show foam-insulated homes sell faster and at modest premiums when the install is documented; without paperwork the upgrade is harder to credit at sale. (2) Future tax programs: federal energy-efficiency credits have come and gone repeatedly (the prior Section 25C credit ended December 31, 2025 under the One Big Beautiful Bill Act); if a future program reinstates similar credits, your closeout paperwork will be required to file. (3) Insurance and HVAC sizing: knowing R-value per surface lets your HVAC contractor size new equipment correctly when furnaces and AC reach end of life. (4) Manufacturer warranty: the product data sheets identify which Demilec, Icynene, or BASF formulation was used and the warranty terms that apply. Keep the closeout package with home records for the lifetime of ownership; Cincinnati-area installers retain copies and can re-issue if originals are lost.