I know people who relocated to the DC area and have been renting their Madison, WI home out on an academic year basis (at the UW Madison) and they come back and stay at their  Madison home a few weeks the summer.   

I have used Bankrate but this is Interest Calculation Method: 365/360 basis and they don't have it.

The cap rate calculates the ROI on an all cash basis (hypothetically). 

If there's a chance of you inheriting the home vs. a sale that's the best position tax wise as it brings the basis in the property up to fail market value at that point- esentially letting you sell tax free. 

Once the family members with disabilities or who are sixty-two (62) years of age or older, or any other family member, no longer reside(s) in the premises on a permanent basis, or the title is transferred, the property owner shall notify the zoning official in writing, and the accessory family dwelling unit shall no longer be permitted, unless there is a subsequent, valid application.As you can see, it's really all up to the zoning department of that city or town, and my guess is that if your proposed use doesn't meet the above, they will not approve it.It doesn't really sound like they're talking about an entirely separate structure, so if that's true then the question about getting bank financing for such construction would be moot, but it's possible I'm reading the above wrong.As far as whether you can build on the empty small lot in general, you'd want to look up the zone of the lot on the assessor page and then look up the Permitted Uses section of the Cranston zoning ordinance to see what can be built there and Zoning Districts Designated to see if your lot meets the minimum lot size to build something.

You may be able to get coverage for the building on a limited basis.  

The only time your depreciation basis in a property will increase, is if you add more money into the property via capital improvements.

So I would look at what 3 and 4 family properties are selling for on a price per door basis.  

My personal debt and passive income.
Anyone can do this. Less than 2 years ago I owned no real estate.

This took, sacrifice, it took giving up immediate wants for long term needs.

Also note I didn’t include ...

I'm a real estate agent in Delaware who works with investors in addition to everyday residential home buyers.