Indeed, there are
duplexes and there are DUPLEXES deluxe that are absolutely grand! Take those near Boston Edison up thru Davison and Dexter [where it gets a bit dicey]. These
brick units often have fireplaces, hardwood floors, balconies front and back, plaster walls, stucco ceilings - excellent woodwork.
There are two on Virginia Park near 12th street I know of having two bathrooms in
both units. Upper and lower. Also these near-west side Detroit
flats [as they are also called] have huge driveways. The long depth of the units [those with three bedrooms particularly] sometimes matched by large backyards. They are homes. Not apartments - though some may be split into more than two units.
There are cases where owner lives in the upper or lower unit - the renter the other. Sure, there are blighted [and vacant units] but drive for example about the bordering areas of mid-town to see existing and restored. Duplexes are coming back and for many areas of Detroit they
never went away.
The only tri-county suburbs matching the size and build-quality of the D's best duplexes I've seen are found in parts of Farmington, F-Hills, Dearborn, and parts of the Pointes. As these are older suburbs they have these types of structures.
Hamtramck has some - mostly frame, sans driveways and large yards. The U of D area has a few side-by-side units. The near west side of Detroit has the most brick splendid structures. Block after block.
Here's one sold - note the duplexes on either side showcasing huge covered porches. You get alot of light as the driveways are wide...
https://www.redfin.com/MI/Detroit/15.../home/79049353