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.

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

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

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.

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

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

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

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

Originally posted by @Rick Albert:Hello Everyone!

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.