Here is an example of the zoning language that expressly permits an ADU: Single Unit B1 (U-SU-B1) U-SU-B1 is a single unit district allowing urban houses and detached accessory dwelling units with a minimum zone lot area of 4,500 square feet.

How much more per month is a detached garage worth in a very cold winter climate and how much will we "lose" from the other unit by not having it available to offer?

It's the lack of knowledge of the process that is the obstacle.

How do you handle these obstacles and commission fees working with realtors?

I am sure things differ case by case, but can you think of any obstacles or challenges with what I want to do?

@Ron Karr  there are literally hundreds of turn key operators in the US.. you may want to narrow down to a region ... then narrow down to a certain market.also don't think you can't get cash flow in CA or OR or WA.. you can.. just not 20 miles or closer to the beach  :)buying out of state presents a different set of obstacles that are very real.. 

The main unit is a 2/2 which I will be living out of, and there is a lofted detached 1/1 garage apartment which I just put under lease this weekend for $1,100 monthly!

I don't want to start doing it here in Spain (or most of the Europe for that reason):1. because of the non-disclosure rules about price history of a property2. because the housing consists of mostly apartments (one of the highest percentage of share of apartments compared to other types of housing like detached and semi-detached houses in Europe) wich means there is little you can do about improvements in a dwelling - you don't control the facade, the roof, the engineering in the building, wich in turn means there is little negotiation room and spread in profits. 3. because in Spanish there is just no literature, blogs, nothing in the internet for wholesaling (as in US version) or deal sourcing (as in UK), so I will be acting blindly4. 

@John D.One of the biggest obstacles real estate investors face is financing.

In my "community housing" which is townhomes and detached townhomes, this is where I get mostly Transitional Tenant's; those who were renting an apartment and saving up to buy a home, family size has grown and working towards buying etc..