Changing our primary residence to Florida. Will we have to pay capital gains tax on our old property when selling?
In order to qualify for like-kind (1031) exchange treatment, the property must be held for productive use in a trade or business or for investment.
See https://www.law.cornell.edu/uscode/text/26/1031
The IRS also provides a safe harbor for such exchanges.
See https://www.irs.gov/pub/irs-drop/rp-08-16.pdf