Tried some stuff
sphinx-build -b html -d _build/doctrees -D latex_paper_size=a4  en _build/html
Running Sphinx v1.1.3
loading translations [en]... locale not available
loading pickled environment... done
building [html]: targets for 0 source files that are out of date
updating environment: 0 added, 0 changed, 0 removed
looking for now-outdated files... none found
no targets are out of date.

Build finished. The HTML pages are in _build/html. now works. Reordered the documentation a bit