Unfortunately, the regulation doesn’t specifically address this type of situation, of course! However, a few things to consider:
1. The intent of the funds from the construction-to-perm loan is to convert the commercial building into a mixed-use structure, so ultimately the loan will be covered by a dwelling.
2. You could utilize the square footage test or the projected income test to determine whether the structure is being utilized primarily for commercial purpose or residential purpose. If you have information regarding the projected income of the retail space you may be able to classify it as primarily commercial and could avoid the HMDA reporting requirement.
3. Based on the explanation that 68% is residential and 32% is commercial, it appears that you may be utilizing the square footage method and it would be deemed residential.
Considering these factors I believe it is a covered transaction that should be reportable as a home improvement transaction.
Because this is an obscure transaction, you may want to consider reaching out to your regulatory agency to seek an opinion as well to ensure your financial institution and the agency are interpreting it consistently.