I would add transform matrix so the d
values do not need to change
<svg xmlns="http://www.w3.org/2000/svg" viewBox="-10 -5 20 35">
<g fill="none" stroke-width="1px">
<path stroke="black" transform="matrix(1.000000,0.000000,0.000000,1.000000,0.000000,0.000000)" d="M13,14H2c-0.5523,0-1-0.4477-1-1V2c0-0.5523,0.4477-1,1-1h11c0.5523,0,1,0.4477,1,1v11C14,13.5523,13.5523,14,13,14z"/>
<path stroke="blue" transform="matrix(0.707107,0.707107,-0.707107,0.707107,0.000000,0.000000)" d="M13,14H2c-0.5523,0-1-0.4477-1-1V2c0-0.5523,0.4477-1,1-1h11c0.5523,0,1,0.4477,1,1v11C14,13.5523,13.5523,14,13,14z"/>
</g>
</svg>

Where the transform represents 3x3 homogenuous transform matrix:
transform="matrix
(
x_scale*cos(x_ang),x_scale*sin(x_ang),
y_scale*cos(y_ang),y_scale*sin(y_ang),
x_offset,y_offset
)"
where x_ang
is your rotation angle of x axis, y_ang=x_ang+90deg
is rotation angle of y axis (if not perpendicular to x then you got skew), x(y)_scale
is the scale in each axis (1.0
) and x(y)_offset
is the origin of new coordinate system in the parent coordinate system so you can use ti to translate/pan stuff.