You shouldn't use RCV for the 5+ residential and commercial building. As Randy stated, you shouldn't use RCV on the single family dwellings either - unless it is a primary residence, but there are other conditions that must be satisfied too. You should use ACV for all of your buildings unless they are primary dwelling, fully insured and a single unit.
If you don't understand the differences between ACV and RCV, read the article entitled "Flood Insurance Insurable Value" found at our website:
http://www.bankerscompliance.comGo to the "Resources" page and then "Free Downloads". You'll find the article toward the bottom under "Articles". Be sure to read the "NFIP Policies" section on page 3 of the article. This will help you understand why type of policy you need (dwelling vs. general).
Once you understand this and get the correct insurance value (RCV, ACV or other value), you can then calculate proper coverage. You're still going to need some amount allocated to contents, however.