\documentclass[english,12pt]{utwente-beamer}
\usepackage[backend=biber,style=authoryear,natbib=true]{biblatex}
\usepackage{lipsum}
\usepackage{siltex}
\usepackage{pdfpc}
\usepackage{tikz}
\usepackage{pgfpages}
%\renewcommand\pgfsetupphysicalpagesizes{%
%  \pdfpagewidth\pgfphysicalwidth\pdfpageheight\pgfphysicalheight%
%}
\pgfdeclarelayer{bg}
\pgfsetlayers{bg,main}

%Disable navigation
\beamertemplatenavigationsymbolsempty

\usebackgroundtemplate{
    \only<second:0>{
        \begin{tikzpicture}[remember picture, overlay]
            \fill[green] (current page.north west) rectangle (current page.south east);
        \end{tikzpicture}
    }
    }

\newcommand{\customslide}[2]{
    \alt<second>{\begin{minipage}{105mm}
        #1
    \end{minipage}}%
    {
        #2
    }
}

\setbeameroption{second mode text on second screen}
\begin{document}
\clearbanner
%% Introduction
\input{content/introduction}

%% Design Method
\input{content/design_method}

%% Case Study
\input{content/case_study}

%% Case Study
\input{content/evaluation.tex}

%% Conclusion
\input{content/conclusion.tex}

\end{document}