Where there is an unheated corridor present for a flat or maisonette it should be included by the user as part of the heat loss wall perimeter in the main property. The length specified in the flats and maisonettes screen is then treated separately - within the calculation - as "semi exposed". Main heat loss wall lengths should therefore always be in excess of Unheated corridor lengths as these are effectively encompassed within the Main heat loss wall length. Where the Unheated corridor (along with an assumed door) is unable to be accommodated by the Main heat loss wall perimeter it will report the following error: "SAP 2005 CALCULATION ERROR : External Wall 1 Area (m2) MUST be greater than 0" The Lifespan SAP Team
SAP Conventions...
Are you getting the error message invalid UPRN when trying to calculate and lodge? Please follow the steps attached. ...