\documentclass{scrartcl}
\usepackage{iftex}
\ifPDFTeX
	\usepackage[utf8]{inputenc}
	\usepackage[T1]{fontenc}
\fi

\usepackage{scrlayer}

\usepackage{graphicx}
\usepackage{tikz}

\definecolor{peitex}{RGB}{240,136,26}

%Hintergrundbild
\DeclareNewLayer[
page,
background,
contents={%
	\begin{tikzpicture}
	\useasboundingbox(0,0)rectangle(21,-29.7);
	\useasboundingbox(-.1,.1)rectangle(21.1,-29.8);
	\filldraw[peitex](-.1,.1)rectangle (1.2,-3.2)(.25,-3.2)rectangle(-.1,-29.8);
	\filldraw[peitex](0,0.1)rectangle(14,-.4);
	%	\draw(0,0)rectangle(21,-29.7);
	\end{tikzpicture}}
]{background}

%Logo
\DeclareNewLayer[
align=tl,
hoffset=2cm,
voffset=1cm,
width=4cm,
height=2.2cm,
background,
contents={\includegraphics[width=\layerwidth]{PeiTeX_logo}}
]{logo}

%Adressfeld
\DeclareNewLayer[
align=tr,
hoffset=\dimexpr\paperwidth-4mm\relax,
voffset=\dimexpr4mm+\tabcolsep\relax,
width=\dimexpr\paperwidth-14cm-4mm\relax,
height=3\baselineskip,
contents={%
	Firmenname\\
	Straße Nr.\\
	PLZ Ort
}
]{addressfield}

\DeclareNewPageStyleByLayers{titlestyle}{addressfield,background,logo}
\pagestyle{titlestyle}

%Sofern Schnittmarken benötigt:
%\usepackage[cam,b4,center]{crop}

\begin{document}
Dokumenteninhalt

\end{document}