Thanks David. For some background on my inquiry, I'm referring to the top of page 19 of the 2016 Flood Q&A below, where it states lenders may use the hazard insurance policy to determine ACV, but adjustments may be necessary since Hazard insurable value is different. I was hoping to see if anyone uses this method of taking the Hazard insurable value, and what adjustments they use. I imagine it's much more complex than a simple formula, but thought I'd try.
https://www.fdic.gov/regulations/compliance/manual/5/V-6.1.pdf"In calculating the amount of insurance to require, the lender and borrower (either by themselves or in consultation with the flood insurance provider or other appropriate professional) may choose from a variety of approaches or methods to establish the insurable value. They may use an appraisal based on a cost-value (not market-value) approach, a construction-cost calculation, the insurable value used in a hazard insurance policy (recognizing that the insurable value for flood insurance purposes may differ from the coverage provided by the hazard insurance and that adjustments may be necessary; for example, most hazard policies do not cover foundations), or any other reasonable approach, so long as it can be supported."