# Free Roof Surface The "Free Roof Area" function is used to enter the roof area that belongs to a previously entered roof contour polygon. When the "Free Roof Area" function is selected, a roof contour polygon must be chosen first. This can be done either in the XoY view or in any other view.\ After selecting the roof contour polygon, a dialog box opens in which the values for the roof area can be entered. Depending on the values entered in the dialog box, different functions for generating the roof area can be selected. It is also possible to select roof contour polygons that already have a roof area. In this case, the existing roof area remains in place until the new roof area is generated. It is therefore possible, for example, to use points of the old roof area when determining points for the new roof area. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.dietrichs.com/dietrichs-intelligent-documentation/docs-de-en/design-program/modellbereiche/dach/direkte-dacheingabe/freie-dachflache.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.