[Tex/LaTex] Geometry package – too much space on bottom

Question

I have an inflexible formatting requirement from my publisher for typesetting the text area. Top, bottom, left, right margins must each be 2cms on an A4 paper. The text area includes all headers and footers. The geometry package – to my understanding – provides all functionality required for achieving the goal. However, in my MWE the bottom margin is just too large. I do not know why.

Highly appreciate your support!

 \documentclass[12pt]{scrbook}

 \usepackage[a4paper, left=2cm, right=2cm, top=2cm, bottom=2cm, includeheadfoot]{geometry}

 \usepackage{scrpage2}
 \pagestyle{scrheadings}
 \clearscrheadfoot
 \rehead{\headmark}
 \lehead{\pagemark}
 \lohead{\headmark}
 \rohead{\pagemark}

 \usepackage{lipsum}

 \begin{document}
 \section{test}
 \lipsum[1]
 \lipsum[1]
 \lipsum[1]
 \lipsum[1]\footnote{test}
 \lipsum[1]

\end{document} 

Answer 1

If there should be no space for footer add nofoot to the options of package geometry:

\documentclass[12pt]{scrbook}

\usepackage[
  margin=2cm,% each margin should be 2cm
  includeheadfoot,% text area includes header
  nofoot,% no space for footer
  %showframe% show the page layout
]{geometry}

\usepackage[automark]{scrpage2}
\pagestyle{scrheadings}
\clearscrheadfoot
\ohead{\pagemark}
\ihead{\headmark}

\usepackage{lipsum}% only for dummy text

\begin{document}
\chapter{Foo}
\lipsum[1-6]
\section{test}
\lipsum[1]
\lipsum[1]
\lipsum[1]\footnote{test}
\lipsum[2-20]
\end{document}

Result with option showframe:

---

Of topic: Note that package scrpage2 is outdated since 2014. Its successor is scrlayer-scrpage:

\usepackage[automark]{scrlayer-scrpage}% sets pagestyle scrheadings automatically
\clearpairofpagestyles
\ohead{\pagemark}
\ihead{\headmark}