Any investors in the Houston area with experience in building an addition for a home to increase square footage and add value?

In an RM-1 building, the minimum unit size varies: for the first 1,440 feet of square footage, you have to use at least 360 sq. ft. of lot area for the units.

If you just looked at comps you would think a certain value based on square footage, bedrooms, etc.

Ie attached garages, basement storage, large square footage, zero lots, etc.

How do you know if you'll be legally allowed to convert a detached garage into living space or create any other type of square footage increase: attached garage conversion, basement or attic conversion, ADU, etc.

Also, aim to get similar bed bath count and square footage and make adjustments if necessary.

I'm suspicious it was a PM problem and not so much a sq footage problem.

There are so many dynamics like specific location, size, square footage, type of home, ARV, utility hooks and a dozen other things.  

Then, I can add value to it by rehabbing and perhaps even adding square footage.

In my case the rental unit is approx 33% of the homes square footage so I can only write off 33% of those items.