@Brandon Eike  That's a decent amount to put down. 

However as Texas only allows a HELOC on your Primary Residence, I don’t want to lose this facility if I move to a new place (and I want to comply with the rules!).

Bryan I would say PLANNING IN ADVANCE is key.Lot's of investors like GA as it's own of the best investment warm belt states in the country.You need to determine if you are going residential or commercial for the replacement property and what deal size.

Rents are up  compared to 2020 in my area.

Would love to talk REI mainly commercial an industrial.  

As the popularity grows and people become more nomadic, I think we're going to see more and more of this.

To better homes in the area and to create a product.

Hey Chris, a few thoughts here.Considering that office is not attached to the house, I wouldn’t add any footage to the total home square footage; however, you could advertise that office space and amount of footage and amenities in your remarks.If you’re a Realtor or are using one for the sale, your local MLS may have fields dedicated to additional footage for other buildings on the property, such as ADU’s.The other point is that typically, perhaps depending upon location, a space needs to have heating to count in the square footage, which this office doesn’t have if I understand correctly.Consider contacting an appraiser to inquire about how they would handle this space on an appraisal, or a Realtor.

You'd probably need to talk to a contractor and the City. 

I'd love to see if I can help.