Question regarding Garage to ADU conversion

[Luka Jozic]

I own a SFH zoned SH-RS in Seminole Heights. The setup is a 3/2 main house with a 1/1 ~550 sq ft ADU above a detached garage.

I’m looking to maximize rental income and would love to convert the garage space under the ADU into something usable. The challenge is that Tampa only allows one ADU per lot, with a max of 950 sq ft of total livable area for that unit.

That means I technically can’t create a second unit, but I can expand the existing ADU, as long as the combined upstairs + downstairs area stays under the 950 sq ft limit.

Here’s where I’m stuck:

- I could design it as an “extension” of the ADU (same address, one unit on paper) and just have a kitchenette downstairs instead of a full kitchen.
- Each level could then be rented separately, similar to how people rent by room, but still under one ADU structure.

My concern is the permitting process and cost. To make the bottom area truly livable requires a lot of red tape. Since I plan to hold this property long-term, I don’t care about increasing official square footage, I just want a functional space.

Question: Has anyone here done a “garage upgrade” or ADU extension like this, pulling permits for essentials (bathroom, electrical, replacing garage doors with walls/windows) but keeping it simple otherwise? Did you run into issues later?

In my neighborhood I’ve seen plenty of similar setups on the market, but curious what’s realistic risk-wise in practice.

Appreciate any insight from others who’ve done this in Tampa or similar markets.

[Jaron Walling]

"Tampa is cracking down hard." - Just another example of why we have an affordability crisis in this country. Outdated zoning laws limit the creativity (and cash-flow) for investors like the OP. 

It's been a dream of mine to do something similar. We have the same issues in our market. Unless your building new construction it's nearly impossible to do a garage conversion. The red tape, permits, and costs far out weigh the benefits.