spray foam insulation
friend has 1500sq/ft 2 story house. built in 1978. dormer in rear of house. 3 bedrooms up. rafter construction. batt insulation in attic. perhaps r-30? some parts of upstairs seemed colder. had all insulation removed and foam insulation applied. 2-3". than shredded cellulose blown on top. r-40 approx now. did not change thermostat setting and says upstairs feels much warmer. would the foam act as a better air infiltration barrier and stop drafts and be the main reason upstairs feels warmer?