The creative side of STRs is definitely a fun challenge, especially when you can make it a reflection of your own vision.

BiggerPockets has great resources on both sides - explore and decide what's right for you!

As a builder and developer in Chicago, I've been on both sides of the 'GC equation' - working with GCs and being the GC ourselves.

I think the freedom of not paying your primary mortgage would be a huge stress relief and allow you to deploy cash quicker in the future and feel safer taking risks when you know your own living situation is covered.On the rental side, I know the magic ingredient in real estate is time and the sooner you get properties, the sooner they appreciate and are paid off by tenants and 5+ rentals 20-30 years from now would definitely be worth more than the one primary.Would love anyone's thoughts on how you would go about this situation!

Your development deal will look much like a flip in the eyes of the IRS since it is 6-9 months as well you'll have the short-term side of taxes, not the capital gains taxing on it.  

On the investment side there are quite a few elderly people in very bad circumstances.

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.

If so it might be hard to sell the management side of the business as the the real estate sales may be also under the same company structure.

Quote from @Garrett Karnath: Quote from @Jason Wray: Garrett,If you are talking about reducing closing costs including the banks side you can ask the sellers for a "Seller credit" which they can offer up to 6%. 

The students have been allowed to live all over the west side of the city, and student rents stayed pretty steady (though they have increased every year that I've been doing leasing).