Heat Calculator Heat Calculator Project Name Exterior Temperature (-20°C) Interior Temperature (20°C) Year of Construction Before 1946 1946-1960 1961-1970 1971-1980 1981-1990 1991-2000 2001-2011 2012-Present Room Type Bedroom Kitchen Living Room Office Entryway Bathroom Garage Corridor Rec Room Width (in Feet) Length (in Feet) Height (in Feet) Wall Insulation R10 R20 R27 R32 R40 If unsure, choose R20