New Construction 2nd Property FHA Financing

[Ryan Kennedy]

Hello Financing Gurus! Here is my situation:

My wife and I currently own an owner-occupied SFR that we purchased 1.5 years ago for 5% down. If we were to get an appraisal right now, we would be somewhere between 15-25% equity.

She is an architect with residential experience, and our next goal has been to find an urban lot in a high-density zoned area to build an owner-occupied 2-4 unit property.... AND..... I think I've found exactly what we're looking for. It may be worth mentioning that the lot has a small building in the back that could be live-able with 10-15k of work. Our goal would be to remodel that and also build a duplex/triplex on the main portion of the lot.  

Now, I'm trying to figure out how to finance this whole deal. We REALLY don't want to sell our current residence (it will be renting at around 1.5% rule as we also have a remodeled garage apt in the back, we want to keep this great income and HODL for potential appreciation!!!). 

Our DTI is going to look terrible with two mortgages, minimal equity, and average income. I've read that we could do FHA on the 2nd home since we are conventional on our first home, but we may run into problems with the aforementioned scenario. We're trying to get the 2nd home for 3.5% down, or as low as possible.

Would love to get some advice to pull this off!