I have found that banks often have rules that try to cover every situation and no one seems to have the authority to look at the specific conditions and then make a decision to deviate from the rule, even if logic dictates differently.
When we purchased our current house (20 years ago) the bank told me I needed a construction loan because the house wasn't 100% completed. I didn't want a construction loan because the rates were higher than the fixed rates at the time. They kept telling me I would need the construction loan to get additional cash to finish the house, although I had more than sufficient cash in savings and I was doing the work myself. This went on for months and I even tried different banks with the same results. In the end I was forced into a construction loan and a year later when the construction loan expired I rolled it into the fix rate mortgage that I originally wanted. Unfortunately for me, the fixed rates had gone up over that year (maybe that was their end game all along). The house still wasn't finished at that time and I never borrowed any additional funds, but I found it so frustrating that despite the fact the bank representative agreed with me, no one could make the decision to allow the use of a conventional mortgage. FWIW, I had excellent credit with no outstanding debt and in the end I paid off the 30 year mortgage in about 10 years.
Maybe you can find another bank or possibly a credit union that is more flexible, but I remember in my case no one could make the decision. Good luck.
Lou
05 Travel Supreme Envoy