When creating a Code, you may if you wish, also include a value for Overall Building Performance. Some regions/countries may use a total building fabric method for compliance instead of elemental values (walls, floors, roof etc). If no value is input for Overall Building Performance, a default value of 0.39 W/m2K will be used for metric models (14.56 ft2 F hr/BTU for imperial models)
This method of checking average performance will only be used if the checkbox is unchecked and a value is input. The default value displayed is an average of the values for the various model elements listed.
Any missing inputs will use the default values, so it is recommended to ensure that all boxes are filled when creating your new Code.