We have long hot summers and relatively short winters here in Biloxi. We've been living in a 90-year old house that has no insulation and lots of 'ventilation' ... meaning lots of undesirable gaps in and around doors and windows, the base of our walls, etc.
The underside of the house is completely open to the ambient temperature outside, so our floors get really cold.
The forced air heating system blows warm air from above, and this heat struggles to get to the floor, thus the temperature beneath my desk is often in the 40-50 degree range all winter -- not comfortable to my feet or legs!
It's because of this situation that I dream of having warm floors in our planned new house of 1200 square feet (slab on grade).
Some people tell me it's a waste of money to install hydronic floor heating in this climate when a single mini-split could heat the whole house if it is well insulated, which it will be since we plan to use ICFs.
Would you bother to install PEX in the slab of a new house in this situation?
If not, how much insulation should I use beneath the slab, if any, to help keep the floors warm enough to not feel chilly?