I'm not sure how long subject went from 100% occupied to zero but it sounds like over a long period such as six months?

This complex has great buildings that are very well taken care of and is 100 percent occupied; it is also located in a great location near lakes and a highway for advertising.  

It would only work for a single family, not 2-4 unit with a non-owner occupied co-borrower.

I then asked the lender if I can just go 20% down non-owner occupied so I can use 75% of the projected rental income toward qualification and he said that even then my DTI would be too high and I still wouldn't qualify.

Im in a spot where im trying to figure out what my next step is.I recently bought a 4plex that I am owner occupying and remodeling as I move through the units (currently moving into the 3rd unit that will be remodeled)Everyday on my way home i pass two houses that are very rundown, one even boarded up.

Not owner occupied.

The only catch with FHA 203K is that you must fulfill FHA's residency condition...meaning you'll need to occupy one of the units yourself as your primary residence for at least 12 months. 

@Rik Hunter the product you are looking for is a non owner occupied conventional loan.

If you can house hack using an FHA loan for units or conventional for owner occupied money, you should consider that as well. 

Here is a list of due diligence item I use on my MHP investments:Check zoning and permitting compliance (city zoning)Check local law compliance (with Sherriff and/or Police)Search City Council minutes for any adverse mentionsCheck with State Department of Public Health's Division of Community Environmental Protection (CEP) for compliance violationsCheck with property neighbors for any disputes or pending legal actions Water - Check with water provider for any open or recent issuesSewer - Check with Sewer provider for any open or recent issues or complaintsElectricity - Check with electricity provider for any open or recent issues Rent roll with space number, name of resident, move-in date, renter or owner occupied, number of occupants, monthly rent, additional charges, current balance due and any relevant notes about the residentList of capital expenditures for the last 3 yearsGet last 2 years of Profit and Loss statementsGet last 2 years of Tax Returns for the LLC/Park12 months of Bank Statements for the LLC/ParkCurrent Accounts receivable statementsBuild proforma for next 5 years using rent roll and expensesGet owed taxes to City/County/Local govGet Insurance Quote of commercial liability insurance2 years of utility billsProperty Tax bills for last 2 years List of park owned home including copies of “rent to own” or sales contractsGet list of vendors and contract status for each vendorTalk with on-site property manager regarding issuesConduct Onsite Property Visit with property managerSpreadsheet detailing who pays all utilities including water, sewer, gas, electric, trash, cable, etc.