Both A and B are multi family apartment buildings.The properties are worth around 1.5-2m.I wish to keep A but sell B; preferably in a tax-deferred manner.A is in an area that has been rezoned and I wish to tear down and rebuild the property as the current building is old and I can get more than 4x the square footage because of the new zoning changes.Is it possible to sell B and use all of the proceeds to fund the development of A in a tax-deferred manner?

Although we'll be losing a good chunk of cash in doing that, our "debt to income" ratio will no longer be a factor (negatively) and possibly get us better loan conditions.

Me and my wife have developed our real estate business the last 4 years and I really wanna streamline it to where we really happy with it and have freedom.

@Jennifer Kobasic I think the deal looks like it will cashflow as you mentioned, but if you're in it for the returns it seems you'll get about 3% cash on cash return with 20% down (assuming you do zero repairs/upgrades) - and probably more like 2 - 2.5% when factoring in closing costs (others correct me if I'm wrong please) - I think most investors look for 7% or more cash ROI though.  

The owners are older couple who would really like monthly income and to sell to us (we've developed a good but fast relationship with them). 1.4M sell price, 4% interest locked in and amortized for 25 maybe 30yrs.

There's a lot of unknown factors here

Is crime rate a factor to consider when buying a property in a particular area?

Part of it is how I present it to my parents as well and that would be a much more expensive development project than one house for myself and them.

I live in a development where there is a ton of house rehabbing taking place just don't know where to start!

You can buy a smaller multifamily and use an asset based, commercial loan, where DTI is not a factor.