Coach house garage vs regular garage w basement for an ADU

[Svend W.]

Hi all

I'm househacking a two-flat home in northern Chicago (Evanston). I know I want to add an ADU, either in the basement or the back yard.

Since parking is a bit sparse on our one-way street and we use the driveway, I think in any case we will to build a garage to attract the kind of tenants we're targeting. I'm considering idea of biting the bullet and building a coach house with a garage.

Our basement is finished and has 2 BR (currently a half-bath, no kitchen), so that could be converted.

So, I think the choice would be between a 1) coach house w garage or 2) a regular garage + converted basement. 

I'm curious if anyone has any thoughts on the pros and cons of one over the other--my assumption is that you can't do both--in this market. The coach house would be considerably more expensive (I think the estimate I got was as much as $200K), though it would also have some obvious advantages to prospective tenants.

Thanks in advance.