We are building a new home in the charleston sic area Hot and humid! The home is 4400 sqft with 2850 on first and 1580 on second with 547 worth of 20 foot ceilings.

I had specs 2 stage 16 seer but am struggling with cost. Original plan was 3 units master suite and study 780sqft, rest of lower level 2000 sqft with high ceilings and the upstairs. Manual j by the builder is about 7 ton

Quote came in for a 5 and a 3 which puts master suite on 5 ton with all the high ceilings. To had a zone capability is not much less than adding a 1.5 single stage with two speed VAM.

So at the end question is with SC coastal cooling days will I below the threshold often enough to have 2 stage make sense? Or could I go 3 single stage with two Speed VAM and get near 15 and be in pretty good shape.

House should be pretty tight foaming attic space and under first floor, also used liquid applied membrane and personally caulked all top and bottom plates,jack studs, windows doors etc foamed all cells, and intrusion points.

Thanks for reading this far!