Calculation of gross energy consumption

First the electricity consumption required for ventilation, appliances and lighting is calculated, taking into consideration the daylight utilisation in commercial buildings. The point of departure is the existing method for calculating that net heat demand of buildings described in SBI Direction 184 'Energy demand in buildings'. The existing method includes heat supply from persons, lighting and appliances. The calculating method was later extended to include a method for calculating method was later extenede to include a method for calculating the energy demand for domestic hot water and addition of non-utilised heat loss from pipes and heat producing installations. This loss is calculated on the basis of loss in hot water tanks, heat and hot water pipes. Heat supply from solar collectors is calculated and deducted from the heat demand. The calculated end result is called gross heat requirement. Next the gross energy consumption for heating, ventilation and domestic hot water is determined by means of annual efficiency for heating installations. In the case of natural gas, the calculation covers the amount of gass metered by the gas company. Distribution loss in the district heating supply system and transmission loss in the electricity supply system outside the property are not included in the calculation of a building's energy consumption. An inventory of the environmental impact is calculated impact is calculated based on the energy consumption measured by the total CO2 production per m2 floor area. The CO2 emission is calculated on the basis of the calculated gross energy consumption of heating and electricity, and on standard values for CO2 contents in the fuels used and emissions from electricity production issued by the Danish Energy Agency. The gross energy consumption is calculated for three examples of buildings: a single-family house, and administration building and a multi-storey building. An appendix gives analyses of parameter variations and different losses and supplies included in the calculations