I recently built my house, its 100% foam, even all of the garage, and the joining wall into the house. The garage has a 2.5t mini split heat pump, house has a 5t pump, 2500sq ft with oversized 3 car garage. I have CO2 detectors, humidity monitoring and never have been close to alarming levels on anything. The house is full electric with people who like to leave every dang light on in the house, also blasting the a/c and heat too. Average elec bill is around 100 per month. it gets around 150 in the hottest of summer or coldest of winter. With the exception of internet, this in the only utility bill I have.
R-value is not really a fair comparison to use when comparing others to foam. Foam insulation seals all the nooks and crannies, and provides an air tight seal, no drafts or air/temp exchange. I was warned about heat pumps being a colder heat, it's not at all since there are no drafts in the house, its very comfortable. Insulation is very important, and will probably be the expense that pays you back first. It amazes me that some people would rather budget furniture, flooring or landscaping etc. before insulation.
R-value is not really a fair comparison to use when comparing others to foam. Foam insulation seals all the nooks and crannies, and provides an air tight seal, no drafts or air/temp exchange. I was warned about heat pumps being a colder heat, it's not at all since there are no drafts in the house, its very comfortable. Insulation is very important, and will probably be the expense that pays you back first. It amazes me that some people would rather budget furniture, flooring or landscaping etc. before insulation.