I've seen estimates that are off by 300% when all said and done (e.g. the original bid was $10k but the final cost was closer to $30k).

If you think you will have it for less than 4 years I would say go with the HELOC because you have less origination costs.

Spend the $25,000 on a deal not a consultant.

They do consult with the "money person" but they don't technically have to.

I am doing my best to accommodate and fix the insulation as well as see if there are programs in place to lower the cost. however i want to be firm with tenant as they are not compliant with paying rent because of the cost of the utilities.

Although it is a short timeframe, I'll ask about their depreciation schedule and will consult with my tax advisor.

Nevertheless, continue monitoring the cracks, and if things progress, consult a structural engineer.

Offering a maybe 10% discount will help grease the wheels and the cost is small.

. :) A zoning change can take up to 6 months, approval isn't guaranteed (despite Aldermanic support), and potentially cost a lot of money (architectural site / floor plans & dimensioned elevations, zoning attorney, holding costs, etc.) 

If there aren't any massive physical problems with the property, it appears you can grow income and equity.You might be able to buy this with little cash out of pocket if the seller owns it free and clear and was willing to finance nearly all of it.