Draw a double line and fill it with a pattern

Question

This is my code:

\begin{tikzpicture}
\draw[double, double distance=3pt,line cap=rect]
(0,0) -- (10,0) -- (10,9) -- (8,9)
(10,9) -- (10,14) -- (0,14) -- (0,4) -- (-2,4) --(-2,1) -- (0,1) -- (0,0) -- (0,3)
(0,9) -- (6,9) -- (6,12)
(0,11) -- (1,11) -- (1,10);
\end{tikzpicture}

This is my output:

I would like to fill the double lines with the north west hatch pattern, is this possible?

Another solution to get the same output with a different code is also welcome, but i would like to have the exact same dimensions. Is there another way to specify a path with the given coordinates and then draw a rectangle/double line and fill it with a pattern?

Answer 1

Almost (strange artefacts somewhere) success with decorations.markings library.

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary {decorations.markings}
\usetikzlibrary {patterns}
\begin{document}
\begin{tikzpicture}[decoration={markings,
mark= between positions 0 and 1step 3pt with{
\path[pattern=north west lines] (-1.5pt,-1.5pt) rectangle (1.5pt,1.5pt);
}}]
\draw[double, double distance=3pt,line cap=rect,postaction={decorate}]
(0,0) -- (10,0) -- (10,9) -- (8,9)
(10,9) -- (10,14) -- (0,14) -- (0,4) -- (-2,4) --(-2,1) -- (0,1) -- (0,0) -- (0,3)
(0,9) -- (6,9) -- (6,12)
(0,11) -- (1,11) -- (1,10);
\end{tikzpicture}
\end{document}

Answer 2

Just an idea. Use even odd rule and define the double line with two independent paths, the outer path and the inner path. I know it's not easy but ...

An example

\documentclass[tikz,border=2mm]{standalone}

\usetikzlibrary{patterns}

\begin{document}

\begin{tikzpicture}[even odd rule]
 \draw[pattern=north west lines] (0,0) rectangle (1,2) (.25,.25) -| (.75,1.75) -| (.25,1.125)-|(.5,1)|-(.25,.875)--cycle;
\end{tikzpicture}
\end{document}