[retiredguy123]

Originally Posted by Cuervo

We enclosed our lanai years ago and when we did, we were told if we added AC or Heat it would be considered another room, increasing the tax.
I don't know how your house is structured, but our lanai was built under our roof line, so it was already insulted, plus there was already a fan in place.
Now our lanai faces west, and we have two sets of sliding doors the one we added to enclose the lanai and the one that came with the house leading to the lanai.
When we are not using the space, the double doors add insulation and when we are going to use the space, we just open the sliding doors to the house, and the lanai temperature with the fan quickly becomes the same as the rest of the house.

What you said in your second sentence is not at all typical. The builder does not install insulation above the ceiling in either the lanai or the garage because these are unconditioned spaces. Most likely, there is no insulation above your lanai ceiling.