It means that when you apply for a loan on a property with a mother-in-law suite, the loan officer can add potential rents from a carriage house or basement apartment (in certain circumstance: see below) when calculating your debt-to-income ratio.

I have been in dealing with with a property that is a B&B, 3 story house with a carriage house. the house is zoned in an area that it could be a 2 family. my thoughts were to rent out the 3rd floor, keep the 1st and 2nd as the B&B and rent the carriage house to contractors. the B&B hasn't operated in the past 2 years, so i would have to start from the ground up.

I've got to echo @Michael Dumler...As an agent, I never recommend timing the market, especially for your primary residence and a "house hack" where you rent out a carriage house or in-law suite may be the best solution to achieve the most overlap among what seems like competing goals.

Some carriage houses might not technically be allowed under current codes, and even if tolerance for legal risk is higher than others', you want to know what's what so you have the right expectations.Good luck!

Another great opportunity would be to build a DADU (detached accessory dwelling unit, essentially a carriage house) if you can get the right owner-occupied property that are zoned R80-R6, RM2-RM20-A, RM40-RM100A, OR20-OR40A and ORI and ORI-A AND in an historic overlay.

jermaine I have an owner occupied triplex that I cover with 1 mil in liability per structure - main house, carriage house.

Or if an income element is attached like my MIL apt or a house with a casita, carriage house, ADU, etc. 

My question is, what should i expect to pay either price per sq foot wise or total to add a carriage house with like a 2 door garage and a 2 bed 1 bath on top(Quality wise I would want somewhere in the middle, not crazy expensive, but not super cheap either).

It took us forever to go from horse and carriage to the automobile.

(To clarify the R-2 zoning, this would allow duplex owners to rent both sides; allow SFH with a basement apartment to rent top and bottom; and allow a SFH with a carriage house to rent both units)My wife, @Erin Spradlin, and I are pretty interested in seeing this change make it to the final version as we bought a SFH with carriage house with some partners this year.