[villagetinker]

Razorbackfan, you need to do some research at Sumter County offices. The building codes were revised (as of 1/1/2015, I think). The results can include any or all of the following: (This is what I recall from newspaper and previous threads.)
1. The newly enclosed area will be classified as class 4 or 5 (I think) living space.
2. The new classification requires additional electrical receptacles.
3. The floor needs to be raised (note I have seen comments regarding water proofing).
4. Split A/C units are not allowed (need to check on this, maybe conditional on the living space classification).
5. Multiple permits required as well as inspections.
6. You will want suitable insulation in the lanai, etc.
Also, there maybe specific requirements for the glass being used to enclose this area, there will be increased taxes, and house insurance, etc.

Good luck with your project.

Do your self a big favor go to sumter county of in Pinellas Plaza and ask to talk to a building inspector about the specific requirements. I have done this twice and they have been very helpful, and eliminated the possibility of me making a costly error.