documentclass[border=5mm]{standalone}

usepackage{tikz}
usetikzlibrary{calc}
usetikzlibrary{backgrounds}
usepackage{pgfplots}
pgfplotsset{compat=1.13}
usepgfplotslibrary{fillbetween}
usetikzlibrary{patterns}
pgfplotsset{ticks=none}

newcommand{newvar}{pgfmathsetmacro}

begin{document}

begin{tikzpicture}[scale=1, transform shape]
    newvar{num}{5}
    newvar{val}{num-1}

  coordinate (A) at (0, 0);
  coordinate (B) at (1, 0);
  coordinate (C) at (0, 1);
  coordinate (D) at (0, 2);
  coordinate (E) at (1, 2);

  tikzset{
        square/.pic={
            draw[line width=1mm, pic actions]  (0, 0) -- (1, 0) -- (1, 1) -- (0, 1) -- cycle;
        }
    }

    tikzset{
        tile1/.pic={
          foreach i in {(A), (B), (C), (D), (E)}{
            draw i pic {square} ;
          }
        }
    }

  begin{scope}[scale=1]
        foreach i in {0,...,num}{
            foreach j in {0,...,val}{
                path (3*j+i, -j+3*i) pic {tile1};
            }
        }
  end{scope}

end{tikzpicture}

end{document}