The ratio of space-heating consumption or expenditures to square footage of heated floor space and heating degree-days (base 65 degrees Fahrenheit). This ratio provides away of comparing different types of housing units and households by controlling for differences in housing unit size and weather conditions.The square footage of heated floor space is based on the measurements ofthe floor space that is heated. The ratio is calculated on a weighted, aggregate basis according to the following formula Heating Intensity =Btu for Space Heating / (Heated Square Feet * Heating Degree-Days).