We re-landscaped so it had a private entrance and yard, and finished the kitchen and had it permitted as an ADU.

Fixed up/separated basement and upper floor with separate entrances and created 2 addresses.

The upstairs has a separate entrance, then 2 bedrooms, kitchen, living area and bathroom plus a door going out to a balcony from the kitchen.

Check out zoning and road entrances. 

Without knowing more details about the specifics of the project being proposed as it relates to your property, it's hard to say if there are any obvious big red flags that could negatively impact your property's future value.That being said, I would try to find out as much information as possible about the new apartment building's design and layout - the two big things I would try to ascertain would be the location of the garage entrances/exits, as well as the location of any outdoor amenity spaces (pools, terraces, dog runs, etc).  

I personally know several families with spouses and children that rent out a portion of their home (finished basement/private entrance room, etc.) that offset their mortgage substantially.

Tell them the gym will be in your unit with a separate entrance where you could control the hours it was open.  

This property has a full unfurnished basement that could be converted into another unit as well with a side entrance.  2.

Investing in Iowa provides superior cash flow, reduced entrance expenses, and knowledge of the local market.

It has private entrance but is attached to house and is not private really so it is basically a glorified room for rent with a living room.