You're increasing the need for hot and cold air dramatically and it's doubtful the existing system will be adequate.But, in answer to your original question - yes you will need a permit.

@Tanya Maslach What was the asking the price and what was your original offer?

Property was on market for about 170 daysI originally started the STR plan for tax benefits and plan to do cost segregation as i fall into high income bracket (37%+ 11% state) saving around 50k for 600k property.I have no plan to personally use the property and this is purely investmentI thought i found a great deal because properties in the area are selling for 205-220 per sqft.

We originally used them for our flips, but now we sometimes wholesale broker through them.

. - BUT, it also appears old and probably a symptom of the original house settling.

I'm originally from BR and still invest heavily and lend there. 

If this is financing for a stabilized property rate carries more importance but rate combined with origination fees, pre-payment penalty and term in which you intend on keeping the loan in place are all considerations which together should help in deciding the best financing option.

Originally posted by @Brandon Brock: Yes Mr.

Your original post has most of the right questions to ask (and find out by yourself) about the developer.

Originally posted by @Greg O'Brien:A lot of questions around a balance sheet.