A few of the most common ways to limit tax exposure are depreciation (mortgage interest, property tax, physical property over a span of 27.5 years, major CapEx that can be depreciated at an accelerated rate, etc.), 1031 exchange and using a self-directed IRA (or solo 401k) to invest in properties.

Collar ties on every rafter would help but the real problem is that span.

Replace 18’ wood lentil spanning the width of the row home with steel beam.

My experience spans beyond Realtor, but I don't need to justify that to you. 

The property has a chain link fence spanning the whole frontage of the property and the lot is in contract.

That is why low income areas tend to stay the same in value with little to no appreciation over a long span of time.   

Saw a REALLY interesting presentation earlier this week from an experienced investor- long and short it was based on a large pool of data starting spanning from the 1970's today and considered many metrics: employment, home equity, interest rates, volatility, foreclosure rate, affordability index, etc.... 

The reasoning is because he has a lien which spans multiple properties, this one included and says an installment sale won't wouldn't release the lean of the property. 

The variable of life span is hard to factor in to know if it is worth it to you.  

It also had a huge unfinished basement that spans nearly 70% of the whole building.