Error message when a Flat/ Maisonette with an ‘Sheltered Wall’ is specified: ‘DATA INPUT ERROR’ – ‘Invalid Alternative Wall Area (Main Property)’ Symptoms Where a Flat/ Maisonette with an 'Sheltered Wall' is specified, the 'DATA INPUT ERROR' - 'Invalid Alternative Wall Area (Main Property)' prevents the user from continuing the data input process during the normal data input procedure. Cause The issue is caused by the fact that where a 'Sheltered wall' is specified, the Area must be automatically calculated by the 'Room Height' (specified in the 'Dimensions' page) multiplied by the 'Unheated corridor length' (specified in the 'Flats and Maisonettes' screen). As the 'Room Height' has not been specified yet this cannot take place which results in the error. Resolution Where a 'Sheltered wall' is specified, please ensure the 'Room height' on the 'Dimensions' page is completed prior to checking the 'Sheltered wall present' tick box. This can be completed by navigating to the 'Dimensions' page by clicking on the '7. Dimensions' link on the list on the left hand side of the screen and completing the 'Room Height' dimension: The previous page can then be re-visited and data entry continued as normal. If the 'Sheltered Wall' check box has already been checked prior to undertaking the above, the page will need to be re-visited and the check box un-ticked and re-ticked. More Information If you are unable to resolve the issue using the above procedure, please raise a support ticket on the service desk and we will be more than happy to assist. To raise a support ticket, go into your Lifespan SAP control panel and click ‘Post a support ticket’