A tool to improve decision-making for buildings in the early design phases : Development and verification of an Excel program

This thesis is about a program called BECE (basic energy and CO2 emissions of buildings) and its development and verification and a second program IDA, which is used as simulation tool for buildings. In the first step two model houses are designed, which are already built passive houses in Sweden. A sensitivity analysis will be made in BECE for the parameter for the corresponding temperature for internal gains. After the simulation in IDA and the sensitivity analysis in BECE the results will be compared. To see if the program is working well different building features will be changed, like the efficiency for heat recovery, the window size and the wall insulation. The results show that the program is not working perfect now. Changes in the building future lead to an increase or decrease in both programs but the total energy demand is changing more in most cases in BECE. As an improvement for the program the calculation for the internal gains through windows and solar radiation should be changed. The heat recovery should not only be dependant on the ventilation losses. A way to determine the corresponding temperature for internal gains should be found