Basement HVAC and Insulation
We are about to have the basement slab poured and the builder did not include any slab insulation. I also have an estimate of about $2500 to rough-in the piping for in-floor heat. The entire house is going to be run off a three zone (basement, 1st, and 2nd floors) forced air system. Three sides of the basement will be nearly 100% below grade with a lookout on one side. I live in Northern MN and we get some cold winters up here.
Is it worth the extra cost to add XPS below the basement slab? My builder says we may not see much benefit from the insulation because the slab is below grade by at least 4' (8' in most areas). When they do walkout basements he includes the slab insulation, but not on lookout and daylight basements.
If we properly run our basement duct with vents lower to the ground and not in the ceiling, will be able to achieve a "comfortable" room temperature? Most of the basement will be carpet and I hope the floor does not feel cold when sitting on it. I don't want to pay for the in-floor system if it's going to be a waste.