The \includepdf command from the pdfpages package inserts the PDF as separate pages into the document. That way, you don't have to worry about margins, headers etc - it simply inserts the PDF pages 1:1 like they were.
If you want to embed the PDF on the page, i.e. to have headers, respect the margins of the document etc. you don't need \includepdf, but you can use \includegraphics. That way the PDF can be handeled like any other image. In your case that would be
\includegraphics[page=1,scale=.85]{Anlagen/Projektplan.pdf}
With that, you can only insert one page at a time. For a multi-page PDF, you would therefore need multiple \includegraphics commands.
Now there are several possibilities how to include the document:
- Include every page with
\includegraphics (probably using a for loop). Still, not a very nice solution.
- Include the first page using
\includegraphics to have the section heading, and include the rest with \pdfpages.
- Have the section heading on the first page, maybe add a short description, and then add all documents with
\pdfpages (as you had before).
pdfpagesonly makes whole pages this is not really possible. Might be better to add the section and perhaps some intro text and then let\includepdffill in the next pages. – daleif Aug 13 '15 at 11:19\includegraphics{Anlagen/Projektplan}instead? – barghest Aug 13 '15 at 11:25