I got three estimates and CVS was by far the highest, and in my opinion not the best.

What companies did you get estimates from? Which did you choose? Did they do a good job?

Thank you

We had Custom Windows, as did our neighbors. Great experience. Sorry yours was not

Same here, Custom Windows did our lanai, handled all permits and paperwork and they were great. We installed full-length sliding glass all around to still get open feeling when wanted. Most of our neighborhood used them also and never a complaint. I'm sorry skippy had such a bad experience with them.

What about A/C and critters?
 

To build on this, I have 2 additional questions. 1. Do you need to add an additional A/C, if you enclose the lanai or just open up the sliding glass doors? 2. When they enclose the lanai, do they somehow seal the interface with the house to keep out the lizards? I ask because we have an occasional lizard in the lanai.

The cost is about $10,000-$12,000 depending on size for double pane glass. If you intend to use all year you should:

Consider a split Heat Pump for air condition and heat
Double pane tinted glass to help cool and heat
Flooring resistant to moisture like tile, vinyl...
Insulate the roof above the Lanai
Tinted glass to help cool

Your taxes will increase.

The contractor will get the permit when you give them the job. I used Custom Windows who did a great job......352-787-9797. They have many different options available. All depends on what you want.

Our taxes did not increase when we converted Lanai to Florida Room. As I recall it is because they are on slightly different levels.

Glass was double pane low E.

We are considering whether to add a split so far 50/50 on whether we will do it.

Had no issues with them. Did good work

Taxes increase if you level the floor to the interior

We used Cook Aluminum and they were great and gave us a good price. Did the work when we were not there which was fine with us. Had gotten a price from another popular company but they kept changing the price and never showed up when they were suppose to, not sure why they are so popular.

And that is why we made sure to keep two levels

Its another room
 

I heard comments of.. if you "glass in the Lanai" it counts as another room.. so more house tax. Suggest you check this out as well.

Taxes go up if you raise the lanai floor to the height of the house floor.

Taxes for enclosed lanai
 

Property taxes do not increase for raised floor in Sumter County. If the homeowner removes the sliders then the property taxes increase. As long as the sliders stay in place you can raise the floor, add a mini-split A/C, add vented A/C or zoned A/C or do just about anything to the lanai and the property taxes will not increase. For Sumter County as long as the sliders stay in place, the square footage does not change.

We removed lanai concrete floor, added vapor/moisture barrier (plastic sheeting), installed new concrete level floor (with tile on top to match rest of house), added zoned A/C, A/C outlets, cable outlets, horizontal slider windows with solid glass wall on bottom, standard style rear door, extended lanai from 10x30 to 14x30, new ceiling with recessed lighting and two new fans and all was done per code. Zoned A/C for lanai could only be added if vapor barrier was in place under concrete. When they kicked out the lanai 4 feet we had them install the new pillars evenly spaced. If you check your lanai, my guess is the spacing between pillars will not be equal. Making the spacing between the pillars equal made the new windows look more consistent. We left sliders in place and the square footage did not change. When we sold the house we advertised it with basic square footage, but reported 420 sq ft lanai with zoned A/C and its own thermostat. I think enclosed lanai with big screen TV on wall and its own thermostat A/C was the big selling point.

If you want to verify or know for your particular county, call property appraiser of permitting department for your county.