Isn't it valid to say "there behind the building is an office"?
There is an office behind the building, or there, behind the building, is an office. However, that is something you would read in a book.
It looks like "behind the office building" to me. There is = youjid (sorry, Arabic text is not enabled)
المكتب خلف البناية أو المكتب يقع خلف البناية أو خلف البناية يقع المكتب أو خلف البناية المكتب، كلها تعنى نفس الشئ