Adding studio above SFH garage

[Jacob Kriedermann]

I'm considering the possibility of building a studio apartment above the garage of my 2 bedroom/2.5 bathroom single familiy home attached to the primary house via a walkway from the second floor as well as having a separate entry, which I think avoids requirements of ADUs in Memphis which the property wouldn't meet and could also be used as an additional bedroom/bathroom. Before reaching out to contractors to assess the feasibility of this, are there permitting and zoning issues that would prohibit this, such as it then being considered a duplex when it was initially a single family home?

Thanks!