A lot of those older houses have corroded cast iron or galvanized pipes.Asbestos - This was use in many house products all the way back to the 30s.Lead-based paint - This was used up until 1977.  

@Mark Enis this is ENTIRELY dependent on the loan product you are using. 

But many people like having a feel for what's going on at their property, and find controlling their reputation and product is easier with small or mid-sized buildings.

I am a partner in a General Contracting business building new Custom and Production homes.

Regardless of the real estate type, I think it’s more productive to just make $600k a year in your job and get some great properties in great locations, enjoy the tax savings, and let time do its thing with appreciation and mortgage pay down.

But its seems like these products are imaginary programs that people have heard of but nobody has actually done one. 

In order to qualify for a 1031 you must have purchased that property intending to hold for productive use. 

Honestly knowing that people can't picture the finished product, I'd wait until you have possession and can post after photos.

My firm offers a portfolio product, but it's a 70 - 75% product depending on numbers.

That would be like giving paystubs to the grocery store when buying a gallon of milk....